Nae, most of my melodies have never been written down, because it's too cumbersome for me with the skills I have now. I just go over and over them till they have stuck, just as I do with any piece of music. When I want to recall it I just order it up and wait till it arrives... if I relax it usually does. A phrase will come and be the key that unlocks the memory.
The melodies change the first several time through till my mind works out the kinks, then only the final version seems to get "saved." And sometimes if I have not paid them sufficient attention they have gotten lost forever.
Now one came the other day that, luckily, got onto the tape recorder before I lost it. It was a different sort of melody from what I usually do, so I was afraid I would lose it, especially the chorus, which had some odd intervals essential to the thing hanging together.
The words are still missing in action though-- I sent them to Amos and didn't save the e-mail where I'd written it, and he hasn't sent it back yet! (C'mon, Big Guy, wontcha post it or send it back???)
When word and tune come together but I am not sufficiently aware to save them both, usually one or the other will save-- whichever one was more important to me at the time.