BTDT.
Our ds12 has always been a wonderfully sensitive guy. He definitely does not fit in with the typical crowd, but over time has found some other kids in our neighborhood who get him. But there were definitely times he'd come home completely perplexed and sad about the lack of fair play and niceness among most of the other kids. Kids can really be NOT NICE.
The things I guess I'd keep an eye on are whether your son has at least 2-3 friends that he can touch base with regularly to not feel so different and 'picked on'. In early elementary, our son did not and he was pretty sad about it. (actually depressed, though he is much better now). Coming out of my own shell to make sure he had regular playdates and now time to 'hang out' has been hard, but necessary.
Sometimes his descriptions of problems would seem like he was making too much of a big deal about something, so we had to walk a fine line between respecting his reactions/feelings and helping him see things from the perspective of other kids.
