Do dumpers ever miss their ex or regret their decisions?

Long story short, she ended it with me and i didnt want to have contact 2 months later after we went "no contact". She blocked me on snap and my phone nr, i sent a friend request on insta and sent a message apologizing for how it ended (i wasnt blocked on insta, she had just deleted me).

The message never said open and after 2-2,5 months i ended up removing my friend request to just move on with my life.

At times i have very depressive phases where i think back to our relationship, the things i did wrong and so on... Had several sexual contacts and keep dating but life just feels overall very empty for me.

She dumped me, so my question is, do the dumpers ever think back or regret their decisions? And does it ever happen that she might reach out. Its been 8 months but it feels like yesterday all happened, having trouble moving on fully. Everytime i meet someone new i end up comparing.