I was in a job for 35 years that, in some cases, wasn't right for my personality. I am a Type A Introvert. I was in a sales job. What made me successful was negotiating with accounts and managing a sales force because I was detached enough to look at things from an objective perspective.
What wore me down was the necessary socializing, cocktail parties, dinners, etc. There is a major event going on right now in Las Vegas with over 5,000 people in my industry. I see my colleagues' posts, and it just reminds me how much I hated the late nights and "sucking up" to people I really didn't care for.
I socked away as much as I could into my 401k, and I'm pretty confident I will have enough money to live comfortably but not extravagantly. Our house is paid for, and my 6 year-old car with 27k miles is paid for as well. It does seem that every month there are expenses I haven't budgeted for, but some are for travel and entertainment, and I won't give up on things to look forward to.
I've been approached a couple of times to get back into the industry full-time, but I will not give up the freedom to make my own rules. I love not having any type of schedule and being able to decide what I am going to do with my time. If a part-time contracting opportunity becomes available I may take it, but I'm very happy being retired. After over 2 years, I'm not the least bit bored.