So when my daughter was about 4, she had free reign of the living-room. We put a baby gate at the bottom of the stairs and turned it into a 20X10 playpen. One day I took a break to the restroom, when I came back my daughter had drawn pictures on the wall at the end of each couch, assigning seating. Each one had "mommy," and "daddy" written underneath it.
Then on a subsequent day, I had come home and found a line in the somewhat form of a sine wave starting at the bottom of the stairs going all the way up to the top. I asked my precious daughter why she had done it, she replied, "I wanted the stairs to be more wavy." I had no reply other than to shrug.
The wave lasted until she was 10, two of the three wall-couch assigment have remained despite numerous scrubings with the drill brush and magic erasers. However, we're about to do a full remodel of the house interior and all of the toddler artwork will be erased to the paints of time.
However... as a side note, she's now top of her class in art school. So, there is that.