You & your limits

They say aim high. How high is high -- is there any measurable limit? How will you know when you're chewing more than you can bite? You set your goal, you say sky is the limit, but no, your teacher tells you not to aim for the sky, "go for the moon". In reality, you are just stretching, like an elastic band, towards the breaking point. If you're lucky, you push past the critical point and get what you want. However, if you're less fortunate, just like the band, you snap into pieces. You crash and burn.

So tell me now, when is enough, simply ENOUGH?