He’s apparently said he was born in 1988. In another thread others mentioned that would make him 21 when he started his PhD, which checks out.
Not that unusual IMO, lots of people start their PhD directly after completing their Bachelor’s. If they weren’t born born in the first half of the year then they’ll have completed their BS by 21 and start the PhD either at 21 or 22.
He’s apparently said he was born in 1988. In another thread others mentioned that would make him 21 when he started his PhD, which checks out.