Followup: I guess I'm still immune to poison ivy

Months ago, I posted about grabbing poison ivy in the woods in New Mexico. It was a pretty funny situation, in hindsight - I had no idea that I'd touched poison ivy until I submitted the photos of my hand grabbing it to iNaturalist. Getting that ID response from the iNaturalist site was pretty funny. The followup is that I spent the next month or so anticipating that I'd get a poison ivy reaction, but I never got one, which means that I am still immune to urushiol, as far as I can tell, and I don't get allergic reactions from it yet. If I were to go into the woods right now and grab poison ivy, though, I'd probably have a reaction - repeated exposures increase your chance of having one. The craziest thing I learned on that trip is that you can get a poison ivy reaction up to several weeks after exposure? I have no idea what the mechanism is there - I've seen some people suggesting it's just oil transferring from your clothes at a later date, which actually seems most likely to me -…