Why is my friend confronting me with an old incident from HS?

My male friend and I chat on FB once in a while, not much. He greets me on my b-days and vice-versa. We are both taken.

A week ago he confronted with an old incident from HS. He claimed that I once said ''You're nothing but a worthless garbage'' and ''I would go out with you, in your dreams'' but said it was deserved because he acted like a jerk back then. I was 14 back then and he was 15. I'm now 30 years old and he's 31.

I have vague memories of a small argument we had back then (I used to have a crush on him) but don't recall ever saying those words. I was shocked and replied with an ''Wow I did, really, I said all that''? He said yes, that he still remembers it clearly but it's ok because it was a long time ago and both of us were immature. HS was an awkward stage for me.

I've apologized for saying those things he claimed I did. I don't really remember that part though. Why did he brought back an old HS incident?

Updates
+1 y
Present-day:
I can't imagine ever talking to someone in that manner. I'm obviously much nicer and mature than my HS version from back then. Still... I don't remember that part. I can't imagine rejecting someone like that. Wow.. I'm shocked I said all that... that he claims about.
Why is my friend confronting me with an old incident from HS?
Post Opinion