you cant't always get what you want

Done.  Well I mean, what do you want from me?  As far as my thought of the day goes, that's pretty much it.  

Oh, FINE, I guess I'll to add some substance to this thought: there are things that you want that you just can't have.  And it sucks.  I wish it wasn't the case, that you could just work hard until you got EVERYTHING that you want instead.  But there are some things that regardless of how hard you work, that will never be able to attain.  And, although I am reluctant to admit it, that is not a bad thing.  If you could get everything you wanted, there would be nothing to aspire to.  Although you need to set incremental, attainable goals in order to promote growth and track your progress, you always need a level that is just that little bit out of reach to keep you motivated to keep upping the ante and continue your personal/professional/intellectual development.

As insightful and logical as that sentiment is, it really doesn't make wanting  and not having feel any better.  Wanting is not a good feeling; we want (there is is again) to act on it, take some sort of action to transform a want into a pleasurable experience for ourselves.  We are motivated- some more than others- to make ourselves happy and pursue our desires.  But when we can't, what are we supposed to do?  Well first, you throw yourself a pitty party (just a short one, it's deserved from time to time), then you take a step back and realize what makes up the thing that you desire- this way, you can break it down, focus on the elements that are more attainable get those and keep the rest of it in the back of your mind until you have made progress.  Then you can work on the rest.  And you might find that it isn't even what you really wanted in the first place.  

You might not be able to have it all or at least have it all now.  But you can get some satisfaction, might not be in the way that you think, but it will be there.  And use that little bit of pleasure to encourage yourself to continue working towards the rest of it that may or may not become yours eventually.  Don't get lost in wanting what you can't have, as hard as that might be, focus on the joy of getting what you can have and let the rest of the pieces fall where they may.  You'll get where you need to be, life has a funny way of working out like that.