Good but still hot and mostly tired

I'm still feeling good, but very tired from the heat and overtime at work. But I'm handling things well for the moment, and am able to think clearly.

My sister's breast cancer has moved to her bones and she will die probably within five years. She recently has said she longs for a master's degree in textiles and design as that's where her heart really is. She studied math at school and had an excellent job at a leading computer company before her cancer came back. As sad as I am for her because she won't have the energy or time to pursue her dream, I couldn't help but think of myself. If I knew I only had five years to live, what career do I wish I had followed or investigated? I couldn't think of any (maybe because I'm so darn tired). I like my job. It's hard physical work, but I enjoy it. I get left alone to do my work, I'm not watched by the bosses all day and I can choose the order and pace (sometimes) of my day. But I wonder, what would I regret if I knew life would be cut short?