Oh man, he sure grew up well didn't he? I adore Neville Longbottom.
DH is only 4 months older than me but graduated hs a year before I did, as he's a July baby and I'm a November baby that was held back in kindergarten because it was decided I wasn't ready for first grade. Course now you have to be 5 by the beginning of September anyway to start Kindergarten so it's not so odd as it was then.
When my older two were toddlers we got a lot of "Are they twins?" which I could see since there wasn't much difference in height, they do look quite a bit alike with similar faces, complexions and both towheads (at the time anyway).
But what kind of made my brain hurt was when they were attending the same school, one in 4th the other in 2nd grades and they still got "Oh, are you two twins?" Um no..they're not even in the same grade, whereas twins (normally) would be. Given the setup of elementary schools and how classes of the same grade will do some things together and switch classes for certain subjects, you'd think they'd notice that they never saw the other brother. Course perhaps the brain hurt was on the other side as well, with people wondering "If they're twins, why aren't they in the same grade?"
Even now they're about the same height and weight with the eldest being just a bit taller. Once the middle child said "But we don't even have the same eye color!" I pointed out that his grandfather and great-uncle, who are twins, don't have the same eye color either.