In reply to FreshSlate:
> I hate when people who lose things get told to "concentrate more" or be more responsible
While your ability to lose things seems to greatly exceed mine, I do agree that that is pointless and thoughtless advice.
I think the better idea is to get into habits that make it impossible to forget.
I could easily forget to bring my toothbrush on a trip, so as soon as I think of it when I'm packing, I go grab my toothbrush and put it where I'll literally have to step on it to get out the door. That way, 1) I've done something with it, thus increasing the likelyhood that I'll remember to bring it and 2) if I do forget, I'll have a very good chance of seeing it before it's too late.
Similarly, when I'm out in the woods or at the crag, I don't spread my things around. An item is either in my pack, on my harness, in use, or in my hand. Those are the only places my things are allowed to be. So if my hands are empty and the route has been cleaned, everything must be in my pack, and I'm good to go. I quite simply don't let myself "just put this here for a few seconds while I go get this other thing"; no, if I need to put something somewhere for a few seconds, it goes on my harness or in my pack.