My buddy dated a girl for 3 years, lived with for 2 years. They broke up and he started a new relationship after 5 months of being single. Too quick? That seems too quick.
Personally, I like to wait a year or two before getting into a new relationship. I just really enjoy the time off. I'm not passing judgement upon him, he can date whenever he wants and I won't give any grief. I just want to analyze this difference in each other's personalities and learn something.
Maybe I'm too high?
I don't think there's a cut and dry answer for this. It really depends on their relationship and their feelings, and how long it took your friend to get over their ex partner. Some people can feel happier with others around, while others prefer being alone more.