sunt pueri pueri. pueri puerilia tractant.
This is a Medieval maxim of uncertain provenance.
The first part of this is a tautology. "Boys are boys." But we, of course, understand what this actually means. We have our own similar tautology: "Boys will be boys," i.e., boys will behave like boys--loud, rude, hyperactive, even violent. I can say this. I used to be a boy.
The second part, pueri puerilia tractant, essentially unpacks the tautology--"Boys carry out childish things."
Another Medieval variant reads:
sunt pueri pueri. vivunt iuveniliter illi.
"Boys are boys. They live youthfully."
While we're on the subject, enjoy another late Medieval celebration of youth, Gaudeamus Igitur!
It's a bargain at 0.99 cents on Kindle (or affordably priced at $11.90 on paperback).
You'll travel back to ancient Rome on a harrowing mission to save the modern world. It's the adventure of four lifetimes.