Well as we all know, all of computing revolves around Unix, and therefore effectively begins at 1970-01-01. I'm... mostly joking, although that's actually basically true for the parts of computing that I personally work in so I actually do use 1970 as the beginning mark for the "modern era" in my head.
I forgot about this one! As to my defence, my first computers didn't sport a date (only TI and TI$) and then came classic Macs, which used the more Edwardian January 1, 1904 as the epoch. ;-)
