Do you give untrustworthy people too many chances?

I give people sixth and seventh and twentieth chances to prove they're trustworthy. If someone has a vaguely plausible excuse, no matter if their behavior has been consistent for years, I will give them the benefit of the doubt and believe them when they say they'll straighten out. And sometimes they do. Temporarily.

I'm so tired. Some people really are trustworthy, but I'm tired of not being able to give up on people who aren't.