When Newton discovered him law of motion, he is 24 years old; Einstein published his theory of special relativity when he was 26. Research shown that human brain reached the top form at age around 22 and after that it starts to decrease. So, when you can't become genius at age 20+, then you are no longer able to put the equal sign with the label genius.
I am 36 this year, 20+ is way too far from me. Too bad I didn't manage to achieve any special task, when I was young, that can brand myself a genius. Unfortunately I discovered that I somehow too sohai, even at my current age. People said no cure for stupidity, so I have no choice but to admit that I am sohai.
I hope even I am sohai, please let me be a happy sohai.