>>82392950NTA but you just don't anon, you just think they are being nice or polite, it's not like women actually try. The myth that men are dense is build on the grounds of women thinking just smiling and not being actively hostile should be enough for anyone to pick up romantic interest.
I spent my whole college years thinking I was just ugly. Now I'm in the work force, a female coworker who was with me told me that apparently a few girls had a crush on me, but I never knew. No one ever actually tried anything beyond what a normal, decent dude being would do.