How do you react when you see someone you cut contact with in public?

I was running errands and on my way home, I stopped for a pedestrian. That person happened to be my ex-best friend, who I haven’t seen for almost an entire year now. We ended things on not great terms and while I haven’t been feeling “miserable” about it, I’ve bee unable to get it out of my head and feel kinda fuzzy about it. I didn’t think i’d react this way and I’m not sure if it’s normal. My life has been better with us splitting ways, but my heart still hurts losing 10 years of a really good friendship.

I was wondering if anyone was in the same boat. Or if you had a similar instance, how did you react? How did you cope and how do you know when you’ve moved on? I thought I was over it, but the wound still felt fresh when I saw his face again.

Thanks,

Mecca