Essays / personality type essay (stress on thesis statement) [3]

We are to write an essay that defines a personality type. The example was "disneyland dads"
The instructor is very particular about thesis statements and im new to all this..well, its been 15 years.
I have several of these, so Im thinking of doing my paper on fair weather friends. i have some ideas on what a fair weather friend is:

a friend when circumstances are pleasant or profitable
most likely to appear when they are in need or, at best, when you are not in need.
a fair-weather friend will only be nice to you if he or she is having a good day, or if he or she gets something out of being nice

expects you to be there for them but doesn't reciprocate

I guess i just need help with a catchy thesis statement mine sound so generic and dull. Ex: fair weather friends are the worst kind to have.

it has the subject and the opinion but its just blah!
i didnt have that great of an english teacher...she taught us that an essay was just a story. when i took my GED i failed that part and learned on my OWN that an essay has a format! I wasnt taught about thesis statements either.

im open to all ideas. thank you for any help you can offer.