Try to build a tower by stacking irregularly shaped blocks. That is possible; Sometimes you reach a height of eight, nine, ten stones. Such man-made "Zen-Steintürme" or "Steinmannli" can be found along river banks and mountain peaks. They hold for a while, then the wind blows them over, or a bird lands on it and breaks the stone towers into the knee.

What is the relationship between skill and height? Take some round stones from a river bank. A two-year-old child will be able to build two stones; A three-year with advanced hand-eye coordination creates three. It takes experience to get up to eight rocks. And only with tremendous dexterity and a lot of Trial-and-Error attempts is it to be more than ten. Dexterity, patience, and experience are at times boundaries.