Ask HN: Search what you've seen on the web before

I find many, perhaps most of my searches lately are for something I've seen before - an article, blogpost, etc. Unfortunately, neither Google nor any of the other search engines I use have been particularly helpful for me lately with this. I use several browsers on several devices, so it's not as obvious as a single browser plugin, though maybe I could make that work if that's the best option. I'm willing to save things to a tool specifically if I have to, but would prefer something that slurped my history.

Does anyone have any tools they recommend for this problem?