"...So, I've always been a big fan of AA. I used to like D for the longest time, but you can't carry as many in your pocket. AAA are fairly useful, but they never last very long. I've never like 9- volts, something about those polarized snap connectors seems so primitive and boorish; and I have this idea about developing batteries that will one day replace gas powered engines in cars...why is everyone staring at me?"
~ the moment young Elon Musk discovered AA wasn't a battery club.