Not only can't be described but is different for different people. It was the closest thing I could think of to compare it to. :-) Salt is a good one too, and colors.

Actually the best comparison is when my husband was teaching me to fish for trout in a river. He said to feel for the 'riffle' in the water, that's where the fish will be. Riffle? I don't feel any riffle. I kept asking him to describe it better because I sure wasn't getting it. Then I felt something funny with the line, maybe a riffle? And bam, caught a trout!

Describing the indescribable...