Yes Peatle- it happens to me all the time!
I will see something or hear some one say something that reverberates and it is like a
voice inside that sticks there until I write something about it.
For example the song I wrote Three Words, Eight Letters - I was in a little cafe having breakfast while waiting for my car to be repaired. This woman came in that I did not know, but I could tell she was distressed. She was a stunning middle aged gal, and as I sat there- the words to the song just kept coming to my head. I have no idea what really was the matter with her, but I just imagined a love story and fictionalized it in my head that I wanted to fall in love with her.
I use my phone a lot... instead of writing ideas on paper - I usually just text myself the idea.
Good topic my friend for those of us who like to write - I am interested to hear from everyone on this.
Jim



