What does "mind your words and deeds" mean?

Watch your words and deeds. Do you know what P and Q mean? Do you know the origin of thinking? It means to care and obey the rules, which means "be careful, be careful" Since the late17th century, Mind your P's and Q's have been widely used, and there are many stories about it.

One of them has something to do with hotels. At that time, there were two kinds of wine containers in some bars in England: pint and quart. The pin is big and the quart is small; In order not to make mistakes when the guests check out, the hotel waiter must write down what kind of container the guests use on the small blackboard in the hotel, where P stands for pint and Q stands for Quartus. Therefore, the hotel owner keeps reminding them of your pints and quarts.

Another way of saying it is from the classroom. Pupils are always confused when spelling p and q. P is written in reverse as Q, and Q is written in reverse as P. These two letters are not only adjacent in order, but also similar in spelling. No wonder the teacher wants to say pay attention to your words and deeds.