Sometimes you just cant see the cache

First, look at any yellow dot. It just sits there, doing nothing. Look at all three yellow dots, they just sit there doing nothing.

But now look at the blinking green dot. Stare directly at the green dot, and after a short while, one or more of the yellow dots will disappear and reappear from time to time.

The yellow dots are there, and your eyes can still see them. But your brain edits them out. You dn't actually see what's there. You see what your brain decides is important.

That's how come, and we've all experienced this, you can look straight at a cache and yet not see it.