Similar to what some have mentioned, I find injuries really affect me now... I don't heal fast or at all. Knees swell. Left elbow flares up. Right foot gets Plantar Fasciitis. Separated shoulder aches constantly. I work while in pain, play while in pain, sleep while in pain... It gets to you. It is a running concern/joke with my wife and kids. I don't take painkillers, but I probably drink too much to mask it.
Lifting weights, I'm battling through sticking points, sections of weakness and compensation... I hate that and don't want to bother. I guess that's why trainers exist is to help you through that.
If it wasn't for hockey, I'd probably be dead. (Hockey injures me though. I'm not 20 years old anymore...)