Similarly, I've been anti-confrontational all my life, until I got in a car wreck where we were rear-ended on the highway and thanks to the airbag I really just had the wind knocked out of me, but ever since then I've figured getting punched in the face is probably not worse and can handle more stressful situations now. Still haven't been punched in the face tho.
For anyone wanting to try this, I‘d just warn that many extremes that humans haven’t evolved to endure (sitting for long periods, spending no time in sunlight, spending too much time in sunlight, eating no fat, eating too much fat, etc) have been shown repeatedly to shorten lifespan. I’d see daily ice baths as an unnatural extreme and wouldn’t consider doing this, at least not for a long period of time.
Humans weren't optimized to endure the unnatural extreme heat of a 175 degree sauna, yet studies point to frequent sauna use being associated with a reduction in all-cause mortality