I've seen it mentioned in various places that there's apparently a positive correlation between AS (and perhaps other ASDs) and looking significantly younger than your chronological age. Obviously this doesn't apply to everyone on the spectrum, but it does seem common enough.
It certainly does apply to me - lots of people seem to assume I'm in my late teens or so even though I'm 30. My skinny build probably adds a little to it.
When I left the local hospital last month after getting my diagnosis confirmed, I thought that might be worth some small celebration, so I went to a bar and ordered a beer. The bartender looked at me askance and went, "And you're over 18?" (which is the drinking age for bars here, 20 if you want to buy for consumption off the premises) Being in a somewhat good mood, I just grinned a bit and said "A long way over it, actually" while handing him my ID.
If indeed there is a correlation here, I wonder what the underlying factors might be? I probably also add to it by, like many on the spectrum, handling myself a bit awkwardly, but I'm pretty sure it goes for my facial features too; slow physical aging, which I guess is a good thing...