He's 10 years older than me.

Hi, i'm very confused and i need help, i've never liked anyone older than me, to be honest, this is the first time i've ever liked anyone, I'm 20 years and he's 31, he's very smart, we have the same sense of humour, we can discuss about interesting stuff, it all feels so nice, but i can't help but think it's weird, what do you think?