There are a few things that generally, can induce a sublime, otherworldly euphoria: psychedelics, a particularly good night sky, connecting over a particularly good chat and a particularly good spa experience. It varies with people.
(Sometimes, there are one-off experiences like the time I cried over a perfect seed of durian and when it rained at the encore of a Sigur Ros concert and stopped EXACTLY at the final note.)
3 years ago, I went for a hammam (Turkish bath) in Istanbul that so inspired me that I went to study for a diploma in holistic massage. (Whose only use so far is for me to say I have a diploma in holistic massage)
Yesterday, I paid 70 euros for a hammam at Kelebek Hotel in Goreme that blew that one out of the water.
For me, creating the hammam/spa to rule them all (HTRTA) is the ultimate application of UX. The goal is to engineer a feeling at the end that feels like orgasm: you momentarily forget every single thing in your immediate reality, you get a sense of existential wonder, literally see stars and feel part of something bigger than yourself.
Its makeup is much like the chicken rice to rule them all (CRTRTA). Any Singaporean can tell you that the CRTRTA is a unicorn; there are many moving parts to control and no one gets them all right: the rice, the chilli, the meat, the ginger.
Here are some things I’ve experienced individually at various spas that can make up the HTRTA (they are all versions flawed by my fallible memory):