Self-ish/less

Where do you draw the line between being selfish and selfless?
I always thought it was best to be completely selfless and then I saw this...

Which makes a lot of sense....

So I'm back to the drawing board - where do you draw the line between helping others and taking care of yourself? Making others happy, but also enjoying the life God has placed before you and making yourself happy? 

It is something I know there is not a clear cut answer to, and I'm praying for divine guidance... 

Any thoughts out there?

Well while you're thinking... check out this story of a very selfless police officer! ...we need to hear more stories about the good in the world, and less about the depressing issues...