Looking back at photographs of him signing for Valencia in July 2007, shaking the hand of a smiling Juan Soler - the president who brought the club to near-financial ruin - it is a reminder of just how much Mata has experienced in a mere four years in eastern Spain, and how his maturity has shone throughout.
Mata's emergence was pretty much the only bright spot of Ronald Koeman's disastrous spell in charge at the Mestalla. Having arrived from Castilla (Real Madrid's B team), Mata has spoken of the initial "loneliness" of joining a Valencia side beset by egos amidst general institutional chaos.
Yet after being given his debut by Koeman's predecessor Quique Sanchez Flores, Mata became a regular under the much-criticised Dutchman and has never looked back.
During his time in the capital Mata had already had his first taste of international success, as part of the Spain side which won the European Under-19 Championship in Poland in 2006. In a squad that also included Barcelona's Gerard Pique and current Sporting Lisbon duo Diego Capel and Jeffren, he won the player of the tournament trophy.
That said, there is no swagger or star attitude about Mata.
A year after being part of the Spain squad that won the World Cup in South Africa, he spent this June as an over-age player captaining the Under-21s to victory at the European Championship in Denmark.
In a recent interview with Esquire, Mata described his relationship with the national team at all levels as "a love affair", and that rather than be insulted by the request to drop down to the Under-21s, he was proud to be involved.
As a real team man, it is easy to see why Valencia coach Unai Emery built his side around Mata after the departures of David Villa and David Silva.
Mata has predominantly featured on the left for Valencia so theoretically could provide competition for Florent Malouda. But he is versatile enough to play in a variety of roles - he is strong with both feet and is happy to cut in from the right, and can even do a job in the hole behind a lone striker.
Mata's goal record in his professional career is just short of one in every three games, so Villas-Boas is getting the sort of forward that he has been looking for - a player with excellent close control and acceleration who can stretch the game, but who can equally drop inside to score a goal.
This recipe served the coach well at Porto last season, where he had Radamel Falcao in the centre with Hulk and Silvestre Varela on the flanks.
While their detractors have lampooned the players attracted by Abramovich-era Chelsea as mere mercenaries, Stamford Bridge sides of recent times have always shown a desire and mental strength that contradicts that caricature.
Mata promises to be a formidable addition to that tradition - while adding a much-needed touch of flair.