People often ask me how to identify poison ivy. And I try to teach them. I think I do a decent job. It’s not as simple as one or two markers. But at some point you just develop an instinct
Those stinkhorns tho :o
I get asked to teach people plant ID sometimes, and people often seem mystified by it, until I explain the concept of "search image". It seems to give them a new way to approach it and seems helpful in most cases. Probably related to what you mean by "developing an instinct".
Poison ivy has a few distinct characteristics that make it hard to miss if you know what to look for.
I know folks who always find arrowheads and fossils on hikes. Same skill, different patterns. This is a black box to me, I never see those things.