I have usually been able to find whatever I have lost or misplaced. Mind you, somethings have taken a little longer to find than I wanted to spend looking. I have occasionally needed to buy replacements, scissors, seam rippers, lots of the same colour of thread, knitting needles etc.
I usually lose stuff, when I have decided to reorganize. There it is neat and tidy in the new allotted space and now unrecognizable. So what is lost? My Halloween stuff, I moved it during the last year, I think it is in a box now but I wasn't able to find the box today. So no outdoor or indoor decorations. I did have candy, so I guess the most important stuff was available for the "trick or treaters" that came to the door.
Knitting: I quite often work with my own design, let's face it, I usually do plain scarves and socks. Any notes become obsolete and lost, obsolete because I generally rip out, start over, more than twice a project. Needles changes, cast on changes all happen on a regular basis. I do take photos and some years I make extensive lists. 2006 I had a great list of projects. This years list was abandoned at the end of March.
I have photographed most of my knitting, of course, I just dumped it into the computer and didn't always rename the jpg, somethings ended up under the wrong file. So now, when I am starting to upload into Ravelry and Flicker, I am having trouble finding certain finished projects.
I have been looking at everything, filed in my personal files and didn't find it all. Some things are back in 2005, and not renamed. Obviously, I have some reorganizing to do on the computer as well.