I think people put "understanding" (along with consciousness, awareness, and sentience) up on a pedestal because it makes them feel special. Just another example of egocentrism like how we didn't think animals communicated, or were aware, or could count, or use tools, or recreation.

Think about all the philosophical waxing and poetical contemplation that's gone into asking what it means to be truly alive! ...And then remember that gut bacteria is most certainly alive and all their drivel is more akin to asking how to enjoy the weekend.