English Proverb

"Physician, heal thyself."

-Meaning:  This phrase relates to the readiness and ability of physicians to heal sickness in others while sometimes not being able or willing to heal themselves. It also suggests that physicians, while often being able to help the sick, cannot always do so and, when sick themselves, are no better placed than anyone else.

Views about oneself

"Beauty is only skin deep."

-Meaning: What is on the outside, might not portray the inside of a person. 

Chinese Proverb

"Once a word leaves your mouth, you cannot chase it back even with the swiftest horse."

-Meaning: Be careful of what you say, because once you say it you can't take it back.

Very Well Known Proverb

"Don't judge a book by its cover."
-Meaning: You shouldn't prejudge the worth or value of something, by its outward appearance alone.

One of my Favorites

"Bitter medicine can heal disability, but the bitter truth can only destroy friendships."
-Meaning: Watch what you say, for if you are always honest with your friends they may misunderstand your constructive criticism.