What's the longest amount of time you spent trying to find something?

My wife lost her wedding ring in May. We eventually found it in November. We were pretty actively looking for it for the whole time. Checked all the vents. Moved the over, fridge, dishwasher, bed, washer and drier. You name it, we checked it. Eventually disassembled the sectional couch and found it under one of the sections. Which was weird because there were no gaps that it should have been able to fall through to get under there. Like, you couldn't slide a penny under the couch.