NEED to, CAN do and WANT to...

需要做的， 能做的 和 想做的。

How often in life are we doing something that we need to do, can do and want to do? Very often, it is really more of need than want, whilst whether we can or not is a separate issue.
What will be your choice if there is only one thing you can do?
Will you do something that...
(1) you need to because of some requirement/expectation of the society??
(2) you can do and it is a waste of your talent/chance if you don't??
(3) you want to do simply because you derive happiness out of it??
You might say that if you cannot do it there is no point talking about whether you need to or want to. But the meaning of CAN do here is more for exceptional achievements that not everyone CAN accomplish, given either your special talent/opportunity.
How wonderful would it be if the NEED is something that you CAN and WANT to do.

I have always been aligning the needs to my wants, while 'cannot' hasn't really come into the picture yet...but it seemed to be getting harder and harder to achieve the equilibrium..