Skilled

The other day, while out for a road ride I became very irritated with some rear shifting issues. Some slow shifting, some missed gears. Basically just really annoying. What was most annoying was that I totally re-did all of the cable and housing a few weeks back so there shouldn't be any issues. But, of course, I'm not exactly the most gifted mechanic so that was called into question immediately as I did the mental run down of possible reasons. I couldn't think of what it could be until I saw this:

woops. I guess a securely fastened battery strap strangling the rear derailleur cable could be the culprit. I can't believe I questioned my wrenching skillz.