>>>Funny, I'm 59, and I'm a better climber than when I was 20. Or maybe I just tried to go up too fast.<<<<

Hah! I know exactly what you mean, and I think your analysis is correct. When I was in my 30's and got back into cycling, I used to obsess about what people in cars were thinking when they passed me on a steep hill. For that reason, alone, I would overexert myself and bonk halfway to the top. Now that my grey hair makes me look like I have no business even being on a bicycle, I care a whole lot less. And because I pace myself, I get up hills a lot easier!