I am the master of sour grapes.
For me personally, yes, this phenomenon takes up a large part of my psychology and motivations. It's a smaller part of the large umbrella of cognitive dissonance, and that is something to be constantly on your guard for.
So yes, if you are resentful and critical of something, its wise to very strongly examine it. If you can't actually accept the truth of what you want, what your needs are, you aren't ever going to be able to get them.
Of course, if you unveil all of this, you have to then be prepared to look it in the face, and methodically set about the steps to make it happen. This is hard.
But yes, sour grapes, watch out for them.