Follow up on the black out - I lost something important

I guess I hid it while blacked out? I am not sure. This happened to me before, most notably very long time ago when I lost important documents and media (which I was able to replace).

This belongs to someone else, and I don't remember the context in which I took it or what I did with it. I don't know how to look for it. I want to think that I'd keep it safe, but when I black out I say or do things that don't make logical sense to me or seem to stem from anything that's real when I'm sober. I was lucky that I didn't experience this in years, at least not in this form.

I don't even have any association that would help me connect the pieces, this whole part is blank. Is there anything a person can do to trigger their memory?