The biggest surprise in the pile of mail from when I was away was a check from my auto insurance company. I hadn't overpaid or anything, they simply had decided they made too much money last year, so they were giving everyone some back. Basically, they hadn't paid out as much in claims as they'd thought they might, and their profits were so good that they wanted to share. Fun! I won't be able to fly to Costa Rica on the refund I got, but it's about 10% of what I pay them for a while year, so a non-trivial amount of money.