"What does: You will find the "thing" you lost in the last place you look for it, mean?"
Once you've found it. Is there anywhere else you need to look?
That is exactly correct. When my children were young I used to tell them that while looking for their lost thing "toys"
They thought I was pretty mean once they figured what I meant.
It did make them think though.
Occasionally, an adult will find that statement quite puzzling.