What do you say?

We've started a few new projects around the house...therefore we've made several trips for supplies. The other day we went to H.D., we were greeted at the door and asked if we could be helped. Well, I had a general idea of where I needed to go but I was in a hurry so I said "Yeah, can you tell me where stair treads are?" The guy paused and thought then he said "Now, what do you use them for?" ?????? I was stumped. It's kinda like when Matthew asks me to explain something so fundamental that there really aren't words to explain. So I marched in place and said "For stairs". Yesterday I was there looking for gromments. I had looked around but again I thought, I'll ask it'll be quicker...no. I again had to explain what they are, what they are used for, and then was told by a second person that they only had rubber not metal??? I might need paint soon...but I won't ask for help.