An elderly professor stood before his class of 20 organic chemistry students,
about to hand out the final exam.

'I want to say that it's been a pleasure teaching you this term. I know you've all worked tremendously hard and many of you are off to medical school after summer. So that no one gets their overall grades messed up because they might have been celebrating a bit too much this week, anyone who would like to opt out of the final exam today will receive a "B" for the
course.'

There was a great deal of delight among the class as students got up, walked up to the professor to thank him and sign out on his offer. As the last taker left the room, the professor looked out over the handful of remaining students and asked, 'Any one else? This is your last chance.'

One last student stood up and took advantage of the offer.

The professor closed the door and made a list of the remaining students. ' I'm glad to see you believe in yourself.' he said. '"You all have A's."'

Sometimes it's easier to take the painless option, rather than see things through when they get hard.  On the other hand, a job well done, that is seen through to the bitter end, is far more satisfying.