Exactly what kona said. Sometimes, just by the fact that you write down "All I can remember is meeting a friend", you can potentially remember bigger fragments. I remembered most of one dream around 8 hours later just due thinking "I've dreamed with a friend....something else?" and writting it in my DJ

About reality checks, it's more the other way around. The more you train your mind to face the possibility that you might be dreaming, the less importance reality checks have. Everyone should still do them, they're really helpful, but in half my lucids reality checks were just a 1% confirmation being myself 99% sure I was dreaming. You just have to think, like kona refered, why you are doing them. At some point, you will do a reality check to confirm that you're dreaming, and won't do a reality check to "see" if you're dreaming or not.

If you read my first DJ entry, you will see that my mind made the RC fail, but I was motivated enough to not let go of my doubts.

Tip: if you think you are dreaming, you probably are

Good luck!