You cannot experiment with your health.

I have found that out.

I will not make myself ridiculous as some mothers no doubt do, by insisting that you wear overshoes, though I remember one Christmas you wore them around constantly without a single buckle latched, making such a curious swishing sound, and you refused to buckle them because it was not the thing to do.

The very next Christmas you would not wear even rubbers, though I begged you.

You are nearly twenty years old now, dear, and I can't be with you constantly to find whether you are doing the sensible thing.
"This has been a very _practical_ letter.