I guess my battery is getting weak. This is the second (third?) time now that I could not start the bike after a dozen+ days of it sitting. I don't have anything added that is parasitic. Seems way too soon to need a battery on a 2011.
Anyway, last night I hopped on to go to my friend's (25 min away) and press the starter and yikes, too slow, and I got some message that flashed and went away, and it didn't start. Tried a second time and it seemed to have no brain left and threw up all kinds of errors - KTRIC ERROR, ABS ERROR, FI ERROR. Geesh.
So I went and got the tool to remove the panel and hooked up my battery box, waited a few min, then started it. "FI ERROR". Turned it off, waited, tried again... "FI ERROR". One more time, same thing. So while it was running I pressed both buttons for a while.... "Error code 24". And I could not clear it so I gave up and just left. As soon as I was moving a bit, the error went away and stayed away.
When I got home later, I looked up error 24... "Speed sensor malfunction".

I could be wrong, but I just think the wild voltage drop up and down just scrambled the computer's functions for a split second and caused phantom errors.
I drove the bike 200+ miles today, no problem at all.