I remember sometime back in the 80's going to see Anderson, Bruford, Wakeman, and Howe. Chris Squire was not in the group at the time.
They had some guy playing all of Chris' bass parts. The guy just stood in one spot on stage and played everything from sheet music. Close to the Edge, And You and I, Starship Trooper, you name it, he just played it from sheet music.
I'm sure those of you who feel strongly about the ability to read sheet music will quickly latch onto that story use it as "proof" of how important it is to be able to read sheet music since that skill enabled that guy to fill in for Squire. And you will proclaim that if it wasn't for him having that skill, there would have been no concert at all. Yeah, I get that.
However, my perspective differs.
I thought the guy on bass looked like a total dweeb standing there on stage playing from sheet music. In fact, I think it was Jeff Berlin, although I didn't know who that was at the time. To me, he was just some goofus who played from sheet music. In an orchestra, I suppose that's fine. But at a progressive rock concert? Gee, how exciting. (yawn)
Having played in a YES tribute band, I knew every single note by heart. So does Chris, obviously.
It was at that moment that I thanked my lucky stars that I never put those crutches on me as a young bassist 40 years ago when I started playing, but rather I learned to play by ear and decipher notes from the recordings which planted those notes in my head, and enabled me to have fun playing those notes on stage without the crutches of needing printed material propped in front of me.
Everyone is different. If you read, and like it, then you get on out there and you rock that world with your sheet music and enjoy life to its fullest! Go man go!
For me, I'll be the guy on stage without the crutches, thank you very much!