Kourtney K with Kid 'They Get So Big, So Fast'

3/5/2013 7:33 AM PST

Kourtney Kardashian with Kid -- They Get So Big, So Fast

It seems like only yesterday, Kourtney Kardashian was self-delivering baby Mason from her lady parts in front of the reality show cameras ... and look at him now!

No seriously, try to look at him ... bet you didn't even realize there was a child in this picture.