One of my on-going projects is a block a month through Annie's Attic.  I get the fabric and pattern for two blocks a month - quite manageable, right?  Not when you lose the instructions for two of the blocks!  I had them in my hand, was talking with Alli's helper that day, did not leave the room, and can't find them!  I put them down somewhere, and will probably run across them in a couple of years, because they have not show up yet, and it's been a couple of months since I lost them.  Luckily I did not lose the fabric, just the instructions, so I was able to reverse engineer one of the blocks from the cover photo of the quilt. The other is much more intricate. I worked out the pattern, but not the dimensions (it came out too small).  I replaced that block with another pattern, and I doubt that you can tell which one is mine in the over all scheme of things!