I can relate to that. About a year ago I wrote a kids song.
The tune kept running through my head and I kept thinking, man, thats a good melody, and the song should go over well with kids.
After about a month, I was playing with some people at a friends house, takin' turns with our own material. Two young girls about six came in and listened. I thought I'd try it out on them, so I played my new kids song.
When I was done Curly says, "Man, I haven't hear that song in years."
It was like a ton of bricks fell on me. The song must of been sixty years old, I heard it as a kid and somehow remembered it.
There is not much of a cure for this problem. Careful attentiveness to what your doing may correct it.
We all do it, come close or do it unaware.