Advice on being a proper warrior.
It wasn't written in a time of strike, as, indeed, the author makes explicit, pointing out that time was when warriors had to go to war at sixteen and so trained earlier and so were illiterate, but that's no excuse nowadays.
You should never bellow at your wife like some commoner, and you should never hit her because she can't hit you back.
People treat all their nephews the same, whether their older brother's sons or their younger's, or even their sister's. The heir to your older brother will be the head of household and should be treated accordingly; his younger brothers can be treated as you treat your younger brother's sons. As for your sister's reserve is required because they are in a different family. Similarly, if your daughter is widowed, and her son is now the head of household, most of the decisions should be left to his paternal kin -- though it's proper to look after them if they are impoverished.
Learn to ride well, particularly if you are poor. That way, you can buy good horses cheap if they are unruly or rambunctious.
Importance of being on time when you assume guard duty.
And many other interesting tidbits.