Keep in mind that you're far less likely, or at least I am, to cruise around listening to your own songs. There are a ton of songs that I've heard a million times but never played. When someone calls it on a fill-in gig, it's there in my head. With your own songs, they aren't nearly as ingrained from repetitive listening.
If it makes you feel better, I filled in at the last moment for my buddy's band a month or so ago. They had a song in the set that was familiar and unfamiliar at the same time. I asked about it later only to find out that I wrote it about twenty years ago. Had I not asked I never would have guessed.