Hahah, yep. Just the other week I had a few roxi's(30) and I was in conserve mode, so I was cracking in half and IVing them. I cracked one in half and placed other half on bathroom counter top and proceeded to mainline the other half. Once done I look down for other half, and gone. It drove me fucking nuts. I got a flashlight turned off lights in bathroom and got eye level with counter top and looked for raised impressions, none. I got on all fours and seached each tile square one by one, nothing. I searched that bathroom for four days straight with no luck. I got a vacuum and cleaned out all debris, and sucked every square inch of that room, nothing. It drives me mad, because it is somewhere and I have no clue where.
I have also placed my goods in spots out of my norm for whatever reason or another and next day check my normal spots of placement for my goods, forgetting that I placed elsewhere forgetting where elsewhere is exactly. Then days, weeks, months later while doijng house work I find lost good's... those are very very nice finds.