Pottery is also what one could consider a sturdy material. Once the soft clay has been burnt to a pot, it holds any content firmly. Which eventually makes the pottery proud of its job as a small wall, and it might try its luck to convince real walls of its ideas. Given that walls are meant to resist, it doesn't make much sense to attack them blindly. Have a look at Day 01, how much smarter the weak grass deals with the issue of overcoming a wall, and have a look at today's tragedy.