J.P.
I had 3 homebirths, so there were no NICU experiences, but my 2nd son HATES stickers, bandaids, etc...but his sensory inout is a bit overwhelimng for him sometimes.
But as far as the NICU goes, In my office, I frequently have to touch feet and that includes children's feet. If I touch a child's foot and they quickly withdraw it from my hand and have their knee up at their face, I can look at the parent and say, "Oh, he/she spent time in the NICU, huh?" They look at me shocked, like how did I know that. They retain a memory of it, whether it's conscious or cellular, it's there.