A difference

Today, I noticed a significant improvement in my bike riding. I made it all the way up Bridle Pass (a medium difficulty street climb) in 21st gear (the hard one). When I started riding in earnest about six weeks ago, I had to ride up in 8th. I feel like I have nothing left to accomplish. Or maybe it's that I have no energy left to accomplish anything. I guess if I built a wee bit more endurance, I could challenge for the polka dot jersey on the Tour.