I'm not completely sure, but I honestly don't think I have one. At least not without adding some really griveous violent crime into the mix. I don't think any educational or financial situation can be bad enough not to be redeemable. As for crimes and lost years, stuff like that will always be a part of you, but in most cases, they need not be the sole -or even major- thing that defines you.
I'm not saying it's easy. In fact, I know it isn't. But when so much of happyness is making peace with yourself in some way, I'm not sure that messing up economically or wasting time can easily remove that possibility for anybody.