What sort of an excuse is “I fucked up!”? Especially when the person using this excuse regularly fails to think or plan, so 99% of the time the fault is that he fucked up?

Why should I have to be put out because someone else fucked up?

Should I just accept it and move on, or should I take the issue up with the person using this excuse and say it isn’t good enough? If I say it isn’t good enough what action can I take to ensure it doesn’t happen again? Should I just stop helping this person out entirely?

All questions that I wish I had answers for!