Unless you're a freaking genius and never had to ask a question (is anyone really that smart?), every person at one time or another has been made to feel dumb by someone who already knew the answer. Or at least thought they knew it. Sometimes we feel dumb only because the answer is so simple. I can't tell you how many times I've received an answer and went "DUH!"
But like I told my children as they were growing up, no one is born knowing. Now that's not saying a person who reads a book or go through a class or workshop without raising her/his hand can't learn something. For the person to even want to read a book or take a class or workshop, he/she had at least one question in the beginning. What is this book about? What will I learn? Sure, I'm digging a little deep, but you get the drift.
To be a well-rounded person, you need to be curious. Stephen Hawking is considered to be a smart gentleman. Some people will even say he's as close to a freaking genius as you can get. But the reason everyone knows this isn't because he knows everything, but because he's curious and he asks himself and other people questions. His talent is that each time he receives an answer he retains that information and then asks another question.
I guess the only time I get frustrated with people asking questions is when they ask the same one every time you turn around. Please write the answer down.
Or I've told them where all the information is and all they have to do is read the material. No. They want me to explain it to them (again). It shows they are not paying attention. Yet I truly don't mind answering questions if it because they read it and didn't understand.
For myself, I often will look for an answer for hours, refusing to ask a person. Because 1) I hate bothering people and 2) I don't want people to think I'm dumb. See. I have that problem too.
Of course, my stubbornness has helped me learn a lot about computers, writing and etc., but as I get older, I ask more questions. Time is precious to me and I no longer have that amount of time to learn a new program or software or method.
I hope I never talk to those who ask questions as if they are dumb, but I might worry on occasion about their reading skills.