Okay, this is totally not how I pictured my first post in the CRK section to be... I was here to do a little research. BUT, hopefully I can tell you this story and it will help you out.
My EDC is a Spyderco Endura 4 in ZDP-189. I love this thing. So, my story begins that I've gotten off work and swapped into work clothes to go up into the attic. It's hot, I'm irritated, I can't get done what I need done (running 12 romex to some new outlets, huge pain) I get done (not finished, done) hop out of the attic. Go shower all the insulation and just nastiness off maself. Next day, getting ready for work, can't find my knife. I take one of my others, thinking that it'll turn up. I get home from work and start looking.
Now, here's where we have some similarity. I retrace my steps, the last time I had it. Did I move it when I put on work clothes? Etc, etc, etc. I finally decide that I MUST have had it pulled out of my pocket up in the attic. So, I go back up. I spend over an hour looking at the attic, trying to see where I've dropped it. No luck. Annoyed and defeated, I go to shower the filth off myself. I open my bathroom drawer to get out the toe nail clippers, because trimming toe nails happens on a whim for me. And there's my knife. In a flashback I remember tossing it in there when I took my shower the day before.
2 important things in this bit: first, I shot myself in the foot by going 'IT HAS TO BE IN THE ATTIC!' Because it wasn't. And after I found it, I know it wasn't. And second: retracing your footsteps is never as accurate as re-acting the day/event. Our tiny monkey brain takes a lot of short cuts along the way when we're doing stuff. We tend to glance over the actual details and when pressed for the 'what did you do when...' answer, we tend to make up what we 'would' do if we were doing it again, right now.
If I were a betting man, I'd bet if you go and polish another knife, and cut an apple. You'll find your knife. I bet it's on the shelf where you keep your cleaning gear. Or where you keep your paper towels. Or in your vegetable crisper where you keep your apples. Could be under the mail if you do it on the kitchen table. Or on the floor it you knocked it off your workbench.
Hope this helps, best of luck.