Upon further reflection: What you wrote is actually central to the idea that I'm trying to express. When I was younger, I thought that I'd always make different

Upon further reflection: What you wrote is actually central to the idea that I'm trying to express. When I was younger, I thought that I'd always make different choices and live my life "better" than older people I knew (e.g. going to the gym everyday for a serious workout), but once I grew up I understood why most people do what they do (e.g. working out irregularly, because having so many other demands on their time and energy makes it hard, or due to injury), and now I'm living much the same way in many areas of life for the same reasons. That's the sad part.