I had this happen with an Ipad!
When I was flying corporate aircraft, I used an Ipad for my Jeppesen approach charts, flight planning and filing, weather research, and several other flight-related tasks. One day in April I was getting ready to head out to fly some folks to Key West, and the Ipad was not in my flight case! I looked everywhere to no avail. It was nowhere to be found. I ended up flying the flight without it, however the aircraft I was flying that day was equipped with a Garmin G1000 setup, so all the IFR charts I needed were in that nav system.
As soon as I got home, I bought another Ipad. Thankfully I kept my Ipad properly backed up, so within a few minutes of getting the new one, I had restored the most recent backup from the old one and I was back in business. I had no idea where the old Ipad had gone.
Fast forward from April to late November and Thanksgiving. We were hosting the whole family at our home for the holiday this year. When we had company, we used our dining room because it was large enough to seat twelve people at the table. Otherwise, we never used the room. The day before Thanksgiving, I went into the dining room to put the leaf in the big table. I walked around to the far side of the table and there, on the floor in the corner, leaning against a curio where my wife kept her cut glass trinkets, was my old Ipad!
Then it dawned on me. My brother had visited us back in April and he was curious about the Ipad. We had gone into the dining room for the demo because The Lovely and Gracious Linda was watching a movie in the den. Evidently I set the Ipad down on the floor when we finished, and I totally forgot about it!
They say that memory is the second thing to go as you get older. I can't remember what the first thing was...