Losing it

The Toronto Star's Cathal Kelly explores hard-to-understand episodes of string players forgetfully leaving their instruments in taxis and other public transport, likening the phenomenon to people mislaying their car keys:

http://www.thestar.com/entertainment/music/article/889046--why-do-so-many-violinists-lose-their-instruments

I have a bad habit of leaving umbrellas under seats in concert halls; but I've never owned an umbrella that would cost thousands or millions to replace. So I still don't get it.