Before Lamine Yamal made his Barcelona debut, Barça had played in the Europa League twice in three seasons and had lost three consecutive El Clásicos.
Then a 16-year-old arrived.
In his first full season, he announced himself to the world, won La Liga, claimed the domestic treble, lifted the La Liga Young Player of the Season award, and finished 8th in the Ballon d'Or rankings. The very next season, he finished 2nd.
Before his Spain debut, La Roja hadn't gone beyond the quarter-finals for years. They had just been knocked out by Morocco at that stage.
Since Lamine became a regular for both Barcelona and Spain, everything has changed.
Barcelona have dominated La Liga despite their biggest rivals assembling a Galáctico-level squad.
Spain have reached three finals, losing only the least important one and Lamine was carrying an injury in that match.
At some point, you have to stop calling it a coincidence.
No, he isn't 100% responsible for every trophy or every win. Football doesn't work that way. But he's been one of the biggest reasons behind the transformation of both Barcelona and Spain.
That's impact. That's greatness.