I've had a similar attitude when offered the chance to do psychedelics again (now late 30's, last done early/mid 20's). My unscientific hypothesis, at least in my case, is that much of the anxiety at the idea comes from:

- Everything was more confusing and uncertain back then so it was less of a stretch. With age, I've spent time developing new pathways, habits, and ways of thinking/dealing that I don't take their upheaval lightly.

As a counterpoint, I'd imagine that this is still why they can be useful as well as intimidating. The more set in our ways we get, the less flexible you are during future periods of stress.

- Association of psychedelics with a less certain and more anxious period in my life. I wasn't terribly depressed or anything but looking back...man, those years can be rough and stressful.

I think on some level I can only guess at, the desire to seek new thought patterns and perspectives feels both less appealing and less necessary. Additionally, it carries feelings and associations with the upending of a hard-won equilibrium (or at least relative stability). Not something I take lightly.

Now, that said, I'm pretty sure a mild trip would be enjoyable and I'd probably be fine doing it if the time/place was right. One thing I still stick by: the intense psychedelic journey clearly holds power and appeal for some, but there's really nothing wrong with a mild trip.

I never understood friends who would eat a strip of blotter or a bag of shrooms each. Sure, you get "totally fucked up, dude" but I personally enjoyed feeling like everything just felt a bit novel and looked a bit off rather than not being able to tell where I was at a given time.