This ^^^^ ... Also, with friends like that, who needs enemies!

Commuting is whole different beast than recreational riding. It's almost like loaded touring. The loads aren't as heavy but you are doing a lot more starting and stopping. I have become a much stronger rider since I started commuting. I was already riding a lot recreationally when I started commuting, but it still wore me out. One thing I found out very quickly is that I had to slow down my pace. I was wearing myself out trying to ride as fast as I do on recreational rides with no loads, drafting other riders and not getting caught by so many red lights.