So my grandparents house is a two family home. The upstairs tenant has lived here for 17 years, The lock on her door wasn't working lately. The tumblers inside the lock were worn down. It just happened I had purchased a new doorknob/lock set for our door, but hers obviously needed it more. I got the set up installed except I could screw it in. I would catch the interior holes with the screw, but as soon as they caught they wouldn't turn, even with a power screwdriver. She accepted the set up with out it being properly screwed. I feel like a failure.