why?

France, afternoon

Why some people are just so slow to understand what they have and they realize how important is what they have only when they lose it? "People" includes me of course....

I looked at myself in the mirror just a few minute ago. No matter what someone can say, I think I am pretty and I am attractive. In a weird way probably, in a not common way, but I know people like me. And I am funny. Well, I can be funny, lately I am not sure of how much fun I am to be around. And I am intelligent. Maybe not the smartest person, but I am above average. And I am quick in understanding things (except when they concern me). I have a lot of interests. Wherever I go, people always like me. I can make friends and colleagues like me (of course, except a few exceptions).

Then why do I feel so much like shit again?