"I am a newby and just started a seed stitch sweater in All Seasons Cotton yesterday. The folks at the LYS said I could not knit bonnet in ASC but needed to knit it in the yarn it called for."
Yarn substitution not allowed - what is this silliness????? Holy Soupnazi, people.
Now, perhaps it's a misguided attempt to save a newbie from heartbreak which might scare someone away from knitting forever, but it doesn't sound conditionalized to me "of course you can, but to get a sense of the pattern, why not try it with the yarn called for first . . .". Why discourage in such a pedantic way when you can teach a larger concept like hand and it's role in design? People who knit/crochet/weave should understand the wonderful complexity of fiber design that is the interplay of gauge and material/fiber. Having to use only the yarn in the pattern sounds like a prison sentence to me. And what if you find a great older pattern and the proscribed yarn is no longer in production? Oh well, none for you?
I love to knit, but I find some attitudes of those who share this love kind of saddening and too rigid. I'm also a librarian, and I feel the same way about some of my fellow practitioners of this line of work. Flexibility, adaptability, that's what I like about both knitting and doing whatever it is I do for money. Can I tell you, line by line how to make a cotton sweater for a 168lb. man with Aran cables on it? No, but I can figure it out for ya. Do I know, off the top of my head, if there is a particular form for attorneys to use in the state of Georgia to get a body exhumed? (Yeah, I figured that out too - the answer is only if you need to test the deceased's DNA, yuck).
Anyone can learn by rote, memorize the facts, but that's what computers are for. Process, adaptation, that's why we have these big brains. Develop the skill of figuring things out, you'll never be stumped again. Or, not for long.