I started programming computers when I was very young. Because of the skills I developed, and because of some connections I had, I got a very high paying job in the data processing department of the Livermore School District while I was still a junior in high school. (I was on independent study at the time.) I literally made more money than I knew what to do with, unfortunately.
A couple of years later, I had been talking to a girl online, who lived in Florida. We met a few times. I've never been all that good at the relationship thing, so this seemed important to me at the time, so I moved to Florida. Shortly after getting there, I learned Oracle PL/SQL and another language I can't remember any more in the course of a few days to get a job at Ceridian Benefits Services; in time I became one of their lead techs with a path into their software development department. Again, more money than I knew what to do with.
After about a year of this though, things weren't working out, and there was a part of me that felt starved. It was the part that enjoyed hiking, enjoyed being outside, enjoyed being fit and in good physical health. I also had a strong feeling that everything up to this point had been too easy for me, that I wasn't getting as much out of life as I wanted to.
So I quit.
I moved back to California and resolved to spend the next few years starting over, completely from scratch; I wanted to take the hardest possible path through life for the next few years. (Boy, I had no idea what I was in for.)
I got into rock climbing, and then got a job as a climbing instructor. I had the opportunity, through my style, personality, will, and determination, to influence people around me. I made a lot of friends, many of whom I'm still friends with. I got to feed the outdoor side of my personality for a while. The job didn't pay much though, and eventually I fled, in debt, to a job in the retail part of the outdoor industry, in another part of the state.
During this time I didn't use computers, unless it was as a cash register or inventory system. For a period of a couple of years, I was completely disconnected from the internet, computers, toys, and gadgets. I learned how to fix cars, I chased sheep down the street, I climbed a lot, and I wandered around.
I'm back in computers now, obviously. It took me only about a year to catch up to the changes in the industry, and I'm one of the leading consultants in my area now, with a successful business of my own.
But, I'm really, really, really glad I took that road. It taught me so much that I couldn't have learned by staying behind a computer desk all day long. It taught me how to relate to people, for one. It taught me how to maintain some balance in my life, and how to pay attention to the needs of my spirit. (My girlfriend, who's reading this over my shoulder -- she's really patient with my need to hear myself talk! -- is reminding me that it's also how I met her, which is probably the best part of all. :-)
So my main point, in so much as I have one, is that abandoning your core skill in an area, and putting yourself in over your head for a while, can lead to some really valuable experiences. You don't need to worry about whether or not you'll still be able to get back in later, or re-acquire old skills; they'll come back, in time. Don't worry about that at all.