According to Marcus Chown in
The universe next door, in a multiple of near infinite universes, you will live to be one of, if not the oldest, person on Earth since you cannot perceive a dead reality. Meaning there may have been some Earths that were wiped out yesterday
It's pretty funny how this all happened though. Just like most of our calendars finish 31st of December the same year, the Mayans just stopped filling out a particular calendar at the end of the 13th Baktun. What many failed to learn was there were other Mayan calendars with dates beyond 21st December 2012.
Inb4 the next Apophis 2029/2036 hysteria.