Okay, so I tell it.
Have been to the university library. Looked through some books, got my ordered books (by interlending), had a coffee and drove the 30 miles back.
When I wanted to open the house door, I noticed that I had my key for mother's home in the pocket but not ours.
Panic, since no-one else in the house for two hours.
Thinking.
I've been to the toilet when at university.
Driving back, hoping for some honest soul.
And when I asked for them at the info, I remembered that loosing them that way was impossible since ... I don't sit down when peeing
They were in the cellar door. I forgot them there when bringing down some washings