It's possible lots of people are quick at closing pop-up/under windows.
I think I generally am quick enough to close a pop-up before the page has loaded, which sometimes/often would mean the Google Analytics script hasn't loaded (depending on how Analytics was setup - the new async loaded at the top of the page would probably have caught me, the older syncronous one at the end of the page would probably have missed me).
I think I generally am quick enough to close a pop-up before the page has loaded, which sometimes/often would mean the Google Analytics script hasn't loaded (depending on how Analytics was setup - the new async loaded at the top of the page would probably have caught me, the older syncronous one at the end of the page would probably have missed me).