When I was young, I worked at a sortation hub for UPS. Later, I left there and worked for what is now Fedex ground as a Sort Manager. I was very good at the small package business. I was tired all the time, BUT those two places were almost custom designed for me. Those jobs were SO fast paced and intense, that I didn't get tired and I enjoyed them. Looking back, if I had known, I should have stayed there. I had tremendous trouble later working at a desk. It was deadly for me. Some days I handled more work than anyone else. Other days, I couldn't get anything done. If you are like me, you need a job that keeps you busy physically. If I am stationary for very long, I am toast.