[ Mind your p`s and q`s ]

The expression can either be written as Mind your Ps and Qs or Mind your P's and Q's.

• "Ps and Qs" is short for "pleases" and "thank-yous".
• This phrase would be used by parents to educate their children to not forget to use those polite words when they speak to people. Possibly, it meant "please" and "excuse me".
• It has many meaning. It can be:

• Be on your best behaviour; be careful of your language. Mind your language.

• To be alert, to be on one’s toes, to be on top form.
• Practice good manners, be precise and careful in one's behavior and speech.
• Mind your manners.

p/s: Please, put your ego in your pocket, guys. 

Seriously, you need to have a sit down with your ego. 

Thank you.