The phrase "I can't do this." really does have a nice ring to it.
After the initial objections (moral or logical) to failure have been overcome, the phrase really does just roll off your tongue. I can't do this. It sounds awful to an overachiever, perfectionist, or pretty much anyone else who doesn't want to see someone fail miserably, but let's face it - when I say "I can't do this" there is a certain amount of relief implied.
"I can't do this." - It's the ultimate excuse for a slacker at heart. It implies:
1) I have given up: I can't do this, I recognize I can't do this, so I have an excuse to be lazy; I couldn't do it anyway, so why bother trying?
2) A substitution of "can't" for "won't": in other words, I've had enough! I refuse to enslave myself for something which cannot be attained!
3) Outside expectations are unrealistic: therefore, they are also unimportant and irrelevant; I did my best, now shut up and don't ask so much of me in the future. I hereby reject your unrealistic expectations and substitute something more reasonable.
4) Don't blame me: I tried, but it's not physically possible. It's not my fault. I'm sorry, but I have absolved myself of guilt and there's nothing you or your expectations can do about it.
That's what it implies. That's the approach that comes with the "I can't do this." statement. Not a good approach, yes? In my humble opinion, here's what should happen in terms of attitude...
1) "I can't do this."? Tough, darlin' - let's try anyway, 'cause it can't hurt.
2) What a cop-out. My dear, my dear, stop wallowing in self-pity. Yes, you may be mentally, emotionally, and physically exhausted, but you can take steps to come much closer to achieving your goal. Odds are, the closer the better.
3) Everyone else IS irrelevant. Make your own expectations; you'll strive harder to reach them. If you expect failure, you will fail. So, get to work focusing on improvement. Nevermind perfection, nevermind complete success: improve. That, you can do.
4) Don't be an idiot - you're still culpable. If you didn't hit your goal, it may not be entirely your own fault, but you making excuses certainly hasn't helped. Responsibility is yours.
I refuse to admit defeat, but it's terribly tempting. It would be so easy to just walk up to a few professors tomorrow and say: "I can't do this."
Because I CAN do this.