Go for it! It's all about passion; if you are passionate about what you do you have something 95% of other folk are missing. And work won't seem like work, it's more like fun. I'm in a similar position; age 38 and with a 15 stint in the finance industry behind me. I've always loved programming, but never thought of myself as an 'enthusiastic amateur'. Now I'm about to take the plunge and couldn't be happier.