i was dreaming that i asked someone if he knew what LD is and if he does that, but i didn’t do it myself in that dream! 
I had something like that happen to me. I dreamed about what lucid dreams were, but I didn’t become lucid! I dreamed that lucid dreaming was like a computer game! weird! 
“damn, i wish i was dreaming now so i could become lucid”
-Wakes up 10 minutes later-
Yeah this can be quite frustrating… 
But these kind of situations are quite common.
In one dream I was totally convinced that it was my job to act in the dream as if I was lucid. I really acted like I was lucid, but I thought it was only a roleplay which I had to follow. So in fact I didn’t really become lucid…
lol!