I'm coming in late on this one, but what the hey...

For me, if I'm going to, let's say, the local shanty sing, and I want to sing a song there that is not among my usual repetoire, I may indeed choose to have the lyrics in front of me. In my case, I do have songs I need to learn for the group, and I have a lot else on my plate besides what with raising a kid, working full time, and trying to get my house in order. Add to this that my memory is for shite. It takes a *lot* of effort for me to memorize a song (tunes are another thing...I can remember them after hearing them once), and so, I personally choose not to devote the brain space unless it is something I will be doing with my group.

In any case, my personal POV on this one is, if it's an informal atmosphere, and I don't butcher the piece, why not use cheat sheets?

I respect that others may not like this much, but I'd hope that they'd forgive me and give a listen anyway.