Well, here's my experience, a common one at that.

I'm dreaming, doing whatever and I either see something [an object, event, etc.] that reminds me of another dream I had, usually one a year or so old. I'd realize that the thing I remembered was in reference to a dream I had and will just shrug it off.

This happens to me whether or not I'm LD, it's been happening to a lot more lately and I was just curious as to why it happens or if anyone else has had a similar experience.