I'm having to use a crib sheet to get me started singing again. It's not something that I like but it's giving me the confidence to sing songs again. I do actually know the song but it's just nervousness. When I first started many, many years ago, I never used a crib sheet (they were actively discouraged) and it took me a very long time to get past my nervousness. I am generally able to discard the crib sheet after the song has been sung once or twice. My progress is much faster than first time around. Singing a song helps it to go into memory.

Ironically I also tell stories and I don't use crib sheets for those at all. Mind you, it helps that stories are in your own words and not learnt word for word. Most storytelling circles ban books.