quirks my brothers have

my brother said I stopped aging once I hit 14/15 years old and didn't know what alumni/ alumnus was. that same brother is roughly 6 foot tall and is only 14 years old. I had to share my calculator with the oldest of my brothers when I was a senior in high school. so one day I had a test and he forgot to give me back my calculator so I wind up borrowing one from my teacher. right in the middle of the test he walks right in and everyone is staring like, Who is that and is he there?