Marriage is the accepted human custom, I believe, especially for royal families?

And I know my brother is well versed in any human custom he practices.

He had never been comfortable with the human custom of shaking hands.

Even more than Woodcarver, the pilgrim had tried to learn human customs.

The table had been set in accordance with human customs.

There were many human customs suggested by this Krug wedding.

She was studying it for practice in reading and to learn about human customs.

It was a human custom that made no sense, and he need not waste time trying to understand it.

The second point I want to make is that you are right; the boy does indeed have to learn human customs.

But maybe that's where the resemblance to human customs ends.