There are pretty remarkable physical differences between a 28yo and a 40yo, yet the legal and cultural differences between those ages are quite a bit less than between 16 and 28.
(And thank god, because the 23-year-old me was both insufferably stupid and didn't know it.)
(Now at least I know it.)
At least we know there's a nonzero probability that your perceived insufferable stupidity is monotonically decreasing. :-)