What is up with my brother?

he's 22. he'll be 23 in may. he always remembers things from his childhood and still likes them. yesterday he was watching schoolhouse rock on his computer and saying it's awesome. he wants to watch malcolm in the middle with me and was watching it on the tv and on his laptop and laughs really hard at it. he used to watch it, he says. is it normal to remember things like that at this age? i'm his 13 year old sister.