I did'nt go back to college and complete my degree [environmental science - Plymouth] until I was in my early thirties, and I was no-where near the older end. I found that colleges like mature students because they tend to be a lot more motivated, having often given up good careers to return to uni.
I also found that treating the course like a job helped. In every morning, productive days [mostly], professional attitude etc meant that I had time to go surfing and sailing, as well as getting assigments in on time.
I ended up with a 2.1 so it worked for me.
Having said that, If you wants to make a lot of money and retire early, take a course in plumbing on the side!