My earliest memory is being in kindergarten (about 4 or 5 years old) and learning how to count using a number line that was posted on the wall. I remember the numbers 1 through 49 were on one wall with 50 in the corner, and numbers 51 through 100 were on the other wall. The number line was black with white numbers.
I believe there is a similarity between our dreams, in the sense that we remember them vividly because we saw them often. Thus, although they may have seemed commonplace, they are very detailed because it was a repetitive image.