What are the gifts of being a parent?

I often think about why certain people become parents, and how they feel about being a parent themselves.

There are some people who accidentally get pregnant and just end up being parents earlier than they expected or wanted.

There are some people who very much WANT to be parents, and I’m also curious why they feel this way?

Is it nature? Is it something inside their head that ticks and says “babies now!”? Or maybe even to gain attention from others?
Or maybe all sorts of things?

I’m truly curious on this topic.