What we do naturally is we cling, we grasp, we hold on to. We are not functioning freely, not free, because we’re stuck. Buddha observed this tendency and gave it a name. He said when the mind is stuck, you’re in dukkha (usually translated from the Sanskrit as suffering). Dukkha literally means a wheel whose hub doesn’t move. So what kind of a wheel do you have? A useless, dysfunctional wheel. What good is a wheel if it doesn’t move? What Buddha discovered and taught was to free up the wheel. He called it sukkha, a liberated wheel, a freed-up wheel. That means liberation, nirvana.