First off, hello to everyone

I've been interested in lucid dreaming for a while but only really started making an effort to learn it in the last few weeks. I've been keeping a journal & making an effort to remember as much detail as possible from my dreams. Last night i think i had my first 'small' breakthrough. A situation came up that just struck me as being a bit bizarre & i can remember saying "im dreaming, this is all a dream"

Here's the problem, i didnt seem to hold on to that realisation & i slipped back into a normal dream state without getting that lucidity back. Has that happened to anyone else? I always assumed the difficult part was getting lucidity, i didnt expect it to be difficult to maintain it.