Set them too low and you're not giving yourself or anyone else a chance. On the other hand, setting them too high sets you up for disappointment. So there must be some happy medium. Hermit-hood is probably not the solution. It's easier than facing reality, but it doesn't get you where you most need to be.
1. We all screw up. Some of us more than others. Me more than most. So you'd think I'd be very amenable to giving people second chances. Or 25th chances, whatever the case may be. But there comes a point when I just don't have much more left to give. They may deserve another chance, but I leave it to someone else to give them that. If only I could go quietly.
2. Just because one person sucked, doesn't mean everyone will. I recoiled today at the site of a new girl in our office. She looks to be about 20 and in the space of 5 miliseconds I thought to myself "No way, not again. I am not going to risk myself for some new girl who might seem like a nice person only to turn around and stab me in the back. No thanks." But then I had to scold myself. She hasn't done anything. It's not her fault those that came before her failed to meet my expectations. See 3.
3. Just because I was foolish enough to expect a little maturity and responsibility doesn't mean I'm going to get it. I am wrong to expect things from others and be angry that they don't live up to my expectations. Arguably, you would expect things out of those you care about. But rather than anger at their failure, it would behoove you to encourage them or at the very least sympathize. Or realize you are expecting too much.
My expectations of others are too high. I give them as many chances as they need. But then comes my breaking point. And once that is reached, redemption is almost impossible. I am as unforgiving as the sea. There I sit in my anger and disappointment, and nobody is hurt but myself. The 'offender' deems me certifiable, and we've both lost. It's not 'nice' to deal out chances like cards. Nothing is gained, nothing learned. Place your bets. If you want another chance, I ask that you understand the stakes.