I feel the exact same way. I just had a lucid dream last night, and even right as I woke up, it had already lost its realism. It was like I was trying to remember specific details from a real life experience a week ago. But like you, after I confirmed I was lucid after my RC's, I remember specifically telling myself, "This is exactly like real life". Now, I can't remember details like the color of the walls, the type of flooring, furniture, etc. However, the logical sequence of events is still fresh in my mind.

I think the key is ADA. In my dream, I never thought to look at the color of the walls, or the type of flooring. Hence, why I didn't remember them. The only thing I remember in full detail is my alarm clock (green LCD, 4 or 5 o'clock each glance, grey casing), because I told myself to focus on it as a RC. So in theory, practicing ADA in real life should allow you to retain the vividness of your dreams in your memory.