I always assumed that the time passed differently in the fairy world than the human...just like Narnia...
Like 10.000 years for fairies would be like 20 years in humans
Because in the new show says Cosmo and Wanda was in vacations for 10.000 years and i REFUSE to belive they left baby poof while he was still a baby..i see them taking their vacations when poof was around the fairy equivalant fo 18 or something...they loved that baby too much
I say that almost 30 years had passed so...let's just assume 28 years.
So lets assume Timmy, would be like 38 ....so the time had pass was 28 years...as he was 10 when had Cosmo and wanda....
10.000 years is 20 yeas sooo
10.000 — 20
X — 1
20x = 10.000
X= 500 years....
So each human year are 500 fairy years...
So they would have raised Poof for 4.000 years and let's say Fairy age slowly but this was enough for him to become 18
So Adult Fairy Poof/Peri is around equivalent of a 25/28 years old because i assume the aging gets slower and slower with time....