One year we were counting up my grandmother's ornaments and realized one was missing - we had to go out to the curb and comb through the tree to find it. It had been missed.
Thankfully we always counted up the ornaments from my grandma (she made one from the year we were born until the late 90s or so). The next year we made sure to count them before putting the tree out!
That's another good thing about fake trees - if you miss an ornament it will be there next year (hopefully, unless you get a new tree).