Who do you think has more difficulty moving on from a past relationship? Men or women?

Whoever has invested more

I don't think there is an either or.

Don’t think that’s gender-specific.
It’s usually the one who felt they didn’t get closure. Or the one who was still hopeful to fix the relationship.

Breakups are difficult, but I think the secret is to feel comfortable with yourself as an individual. A good partner will make you feel more complete, but when it ends you have to feel comfortable with the completeness of yourself.

it depends on how attractive the person is, and how much he/she gets hit on

It varies. It's not a definite gender thing.

Depends on the person... Either can be vulnerable