Why do I like the song best I ever had Wen I had a gf and it was our song?!
I don't really understand your question but maybe it reminds you of her and that makes you happy or maybe it's just a good song so you like it..
This does not make sense and cannot be answered.
Mate u still like her
Because some where in you, you still might like her and by you hearing that song might remind you of the days you were with her :)