I've noticed something odd lately. I've had a rash of upvotes from a number of long-dead topics. Four of the last five came from topics a year or more old, the last two from the same topic which was locked 7 years ago (rating still works, of course). I can't see that much of my history, but I think this trend continues with like 7-8 of the last 10 upvotes. Before that, or there-about, the pattern is normal -- almost exclusively recent topics.
Anyone else noticed this pattern?