The mother of a wise man once said: "Life is like a box of chocolates; you never know what you're gonna get."
This maxim can also be applied to precocious teenage footballers. Some explode onto the scene with a tenacity and verve that they maintain long into their 20s. Others are billed as the greatest thing since sliced bread, but ultimately fail to live up to their own hype.
This list deals with the latter: The players who defied the scouts, the managers and the media by falling short of standards they set themselves at an early age...
At 14 years old, Freddy Adu had the world at his feet. He was the youngest athlete in US history to sign a professional contract when he joined DC United, instantly becoming the poster boy for US soccer.
He starred in a commercial with Pele, Jay-Z rapped about him and his reputation preceded him all over the world.
However, after disappointing stints in DC and with Real Salt Lake, Adu made the move to Benfica in 2007. He was then loaned all around Europe before returning to the States with the Philadelphia Union.
Adu is still only 24 but has played for nine clubs in nine years, scoring just 27 goals in the process.
Adu isn't the only youngster to be touted by Pele as the game's new superstar: The Brazilian legend was suitably impressed with a 15-year-old Robinho, who then went on to help his old club Santos win the Brazilian Campeonato of 2002 and 2004.
In 2005, he made the move to Real Madrid, where his flamboyant skills helped earn two La Liga titles under Fabio Capello.
However, Robinho still wasn't quite the player he had been in Brazil, and things only got worse during a disappointing spell at Manchester City. He then moved to Milan, where he has now outstayed his welcome, with a move back to Brazil looking likely this summer.
Robinho is a classic example of a precocious Brazilian who moves to Europe and fails to live up to his South American reputation.
The last slide mentioned a precocious Brazilian who moved to Europe and failed to live up to his South American reputation, which leads us nicely to Kaka.
After attracting attention with Sao Paolo, Kaka was brought to Europe by Milan, whose owner Silvio Berlusconi described the €8.5 million transfer fee as "peanuts."
The devout Christian became a Serie A sensation, picking up a Champions League medal and a World Player of the Year accolade in 2007.
In 2009, the celebrated attacking midfielder moved to Real Madrid for a hefty €68.5 million, where he was expected to become a legend.
Unfortunately, three weeks later, the Spanish giants paid €93.9 million for a young man named Cristiano Ronaldo, and Kaka has remained in his shadow ever since.
Kaka's place in Los Blancos first team is no longer a guarantee, and he's not among the greatest players in Madrid, let alone the world.
Like a certain Mr Rooney, Francis Jeffers made his debut at Everton at a young age and showed a great deal of potential.
The "Fox in the Box" signed for Arsenal in 2001 for £8 million (one of their highest transfer fees at the time), but he ultimately failed to fit in among the likes of Dennis Bergkamp and Thierry Henry.
Injuries helped his career spiral downwards, and after various short spells across England, he moved to Australia to join Newcastle Jets. He then moved to Malta with Floriana and was last seen at League Two side Accrington Stanley.
He last made headlines for threatening his father-in-law with a broomstick.
Portuguese winger Ricardo Quaresma had everything: Pace, sublime technique and more tricks than a David Copperfield show.
After leaving Sporting in 2003, however, Quaresma endured utterly fruitless spells at Barcelona, Internazionale and Chelsea, punctuated by a reasonably successful stint back in his homeland with Porto.
Showing that he was outside his comfort zone away from the Iberian peninsula, he then went on to Besiktas, where a bust-up with manager Carlos Carvalhal led to an indefinite suspension.
In December, the Turkish club paid out the remainder of his contract and he is now in Dubai with Al Ahli.
Quaresma promised so much, but his confrontational personality and perceived selfishness on the field proved to be his undoing.
Joe Cole was a talented product of the West Ham youth system who enjoyed great success when he broke into the Hammers' first team in 1998.
His eye for goal and penchant for "showboating" caught the attention of Chelsea, where he moved and won three Premier League titles, three FA Cups and two League Cups.
Despite the trophy haul, Cole was often criticised for ignoring defensive duties by Jose Mourinho, and, after a series of injuries, ended up at Liverpool in 2010. When Brendan Rodgers arrived, Cole was deemed surplus to requirements, and he ended up in France with Lille.
Now, he is back where he started at West Ham. Many teenage prodigies achieve less than Cole, but so much was expected of him on domestic and international levels.
Off the field, Eric Djemba Djemba was famous for spending lavishly, reportedly owning a fleet of 10 luxury SUVs at one point. On the field, he became known as an extraordinary disappointment.
Picked up by Manchester United from Nantes, the aggressive Cameroonian midfielder was supposed to be the new Roy Keane. After 20 games in two seasons, it was apparent that he was actually one of Sir Alex Ferguson's poorer signings, often failing to perform in big games.
He was sent to Aston Villa, where he was similarly underwhelming, before spells in Qatar, Denmark and Israel. Currently, the 32-year-old plies his trade with Israeli Premier League side Bnei Sakhnin.
Jose Antonio Reyes signed for his beloved Sevilla at age 10, reportedly using some of his early pay checks with Los Rojiblancos to have a mosaic of the club crest put at the bottom of his pool.
After impressing Arsene Wenger with his pace and versatility, Reyes formed an important part of Arsenal's title-winning squad of 2003-04.
However, the tricky winger often complained of being homesick, and his performances subsequently suffered. He was loaned to Real Madrid in 2006 and transferred to Atletico in 2007 before eventually skulking back at his childhood club Sevilla in 2012.
Portuguese striker Nuno Gomes caught the world's attention at Euro 2000, where he scored four goals but received a seven-month international ban for pushing the referee in the semifinal.
He subsequently earned a €17 million move from Benfica to Fiorentina, which was sadly cut short by the Italian side's financial collapse. Back at Benfica, Gomes struggled to earn a starting place before gradually fading into the reserve side.
After being released by the club, Gomes spent a season at Braga and then headed to Championship side Blackburn Rovers.
Rescued from a crime- and drug-infested Nottingham neighborhood by the YTS scheme, Jermaine Pennant showed huge promise as a youngster. At 15, he earned a record £2 million transfer to Arsenal, making his full debut as a 16-year-old in 1999.
However, a combination of homesickness and disciplinary issues led to a string of loan spells, before he was picked up by Birmingham. A drink-driving conviction meant he had to play with an ankle monitor, but this didn't stop Pennant earning a transfer to Liverpool in 2006.
After disappointing at Anfield, he eventually moved to Real Zaragoza, where he spent most of his time on the bench and was disciplined for consistently turning up late for training.
Pennant was subsequently picked up by Stoke, who released him at the end of the season following a brief loan spell at Wolves.