So you're the one cursing all of these weddings? And here I was thinking it was me.

I think it's just a thing that happens - people change a lot in their twenties, and we don't always realise it to begin with because we think we're grownups now and that's that. From where I'm standing (quite a long way away from marriage), it looks as if marrying young involves specific difficulties and there's probably fair amount of luck involved to make sure that you're both still right for each other a couple of years down the line. Just remember that divorce is generally a far better option than continuing a dismal marriage, and the people who have admitted it are sparing each other more unhappiness, and coincidentally sparing their friends from some even greater social awkwardness.