Not "sour grapes" I think, but the reality
A friend of mine who (to my surprise) voted to Remain put it very well, and summed up my own feeling:
"What actually is the point in leaving - we're in the EU for all its faults and doing pretty well. Leaving is bound to be a step back"
Indeed, getting one's own country "back", etc etc. Everything is a step "back". The world is moving closer together and it makes no sense whatever to try to swim against the tide. I appreciate that for many people "swimming with the tide" seems claustrophobic, dull and contrary to the spirit of "freedom", and no doubt there is a longing for the "old days" and the idea somehow we can somehow go "back" to a time which may have been more "independent" but which, frankly, was pants :-)
Immigration is here to stay, in some form or other. The govt could not control non-EU migration any more than it could EU migration, by the way.
I loved the comment by David Aaronovitch about David Davis in the Commons the other day: "Hiding his astonishment that he had been let back anywhere near government again" or words to that effect. That word "back" again :-)