Left behind again, and again, and again.
The straggler was abandoned by all of mankind due to a cloaking technique unknown even by God.
“Why was I the only one left behind? Why did this happen to me?”
[In the end, even after God had devised a list of all the humans meant to be transported to another world, he could not find you. You said it was a truly phenomenal cloaking technique, right?]
So I, alone since birth, began my lonesome daily life on Earth, awaiting humanity’s return.