I don't have a very popular blog -- roughly 60 followers not counting bots, and about ten of those are ones I actually see in my Activity feed. So I check my Activity feed compulsively, and occasionally I see that one of my older (well, one-year-old) posts has been reblogged.
And you know, I always wonder how people find my older posts. If you click the header (the area around the OP/reblogger’s icon) an old post, then ones from just before it also show up, as if you’ve teleported through their dash to that date.
Sometimes my recently-reblogged older posts have a tag, so I imagine that whoever reblogged it just found a tagged post they were interested by and started trawling all of my posts with that same tag. But on occasion, they reblog an old post with *no* tags. I can only imagine they were trawling one of my tags and took a detour. Clicking one of the specific posts, then letting the same-time posts fill the screen to resume scrolling on (speaking of that, I need to tag all my posts so they’re easier to trawl through). Or maybe it just showed up in the For You page.
I've posted at least one other post about page-trawling, but I don't know if I'll find it, so I'm posting this separately. I think lurking/archive-trawling should be easy to privately do without getting any comments about it, especially since I lurk and trawl too, but it's (i.e. old-post reblogs) happened a few times recently and I guess I just wanted an excuse to remark about it.
Carry on lurking as usual.