For me, being RE has allowed me to fulfill a lifelong goal (and by lifelong, I mean this goal has persisted throughout my life from pre-teen until now). I can't describe how awesome a feeling it is! This is a work-intensive goal, meaning it's not something relatively benign such as pleasure traveling (which we do a lot of also) and the fact that I can either stay up until 2 am learning HTML or wake up every day between 3am and 5am to work on my writing means that I can use the best of myself on my goal, instead of the best of myself on my paying job and have a modicum left over to expend in the mornings, the nights, or the weekends.
I was and always have been a driven person and excelled at my jobs, but I would put so much pressure on myself that my home life would suffer. That has completely changed. Now that we're both retired, my husband and I are almost like different people! Our essence is the same, but we've relaxed so much compared to how we used to be beforehand.
Our last traditional paying job was my husband's, he took a job for about 8 months that we didn't need--we were for all intents and purposes retired already but I suppose we didn't really accept our good fortunes yet. We have investments and rental income that not only pay for our expenses, but also allow us to reinvest some of the rental income in stocks. Still, since my husband is paranoid about money he took a FT job. Even though I was at home and doing all the work there (meaning EVERY SINGLE THING was taken care of for him except he still had to chew his own food, haha) while also working on my own projects, it was terrible compared to how it had been for the half-year that we were retired.
We travel full-time, and to us it's become just our lifestyle. We're entering our 4th year of full-time travel as of last month. I always wanted to do this (I never ever saw myself working at a traditional job until 65), but the reality is so much better than what I had imagined, because I had imagined myself being the same stressed out person while not having a job! In reality it's infinitely better.
What the essence of my post is about, is that there is a deep, deep relaxation that comes from being retired (monetarily securely) that I did not understand or appreciate until I experienced it.