Changing careers

Working full time and still going to school is a lot harder than I thought it would be. I'm a service technician at a local equipment company, but I don't want to be breaking my back for my entire life. I figure I have about three years left before I start to seriously damage my body with all of the heavy lifting and hard work I do around the shop. I can't go full time, but as I can afford them, I've been taking x ray tech classes at a local college ever since Marie gave me the 411 on that industry. Being an x-ray technician seems like it will be a pretty hard job, but it seems to be more mentally straining than physically straining, which is what I need. I have a strong mind and a strong body, but I don't know how much longer my body will hold up. If I continue at the pace I am, I'll be a broken old man by the time I'm forty.