is this an example of an epiphany?

not really unless you're an adult at the time you realized it. An epiphany is a realization which changes the way you look at the world. A massive discovery which changes a sense of self.

...You've seen "The Light" ! ...it has all now become clear. (kinda-sorta when you finally realize that Obama is a Marxist-Socialist, "Nanny")

if you came to it yourself then yes . if your bully of a big brother told you then its just MEAN