Quotes that advise people not to belittle themselves include:

Man should respect himself and regard himself as worthy of the most noble things. ——Hegel

It is not advisable to belittle oneself when one has a great spirit of lofty ideals. ——Zhuge Liang

Chu Lan was born in a deep forest, and does not lose her beauty because there is no one around; a gentleman cultivates virtue and does not betray poverty because of poverty. ——Zi Lu

You should believe that you are the strong man in life. ——Hugo

A person's ability to achieve success only depends on whether he has self-esteem and self-confidence. ——Socrates?

If you think you can, you can; if you think you can't, you can't. ——Davis

I am born with talents that will be useful. ——Li Bai

Confidence is the first secret to success. ——Edison

There is no greater sorrow than death. ——"Zhuangzi"

If life deceives you, don't be sad or impatient. You need to be calm in gloomy days. Believe it, those happy days are coming. ——Pushkin

The word "impossible" can only be found in the dictionary of fools. ——Napoleon

Everything in this world is accomplished through hope. A farmer would not sow a grain of corn if he had not hoped that it would grow into seed; a bachelor would not take a wife if he had not hoped to have children; a merchant or craftsman would not work if he had not hoped to gain a profit by it. ——Martin Luther

In real life, every great deed begins with faith and takes the first step with faith. ——August von Schlegel

Perseverance in goal is one of the most necessary sources of strength in character and one of the weapons for success. Without it, genius will work in vain in the confusing path of contradiction and uncertainty. ——Sir Charles Deferr

Believe in yourself first, and then others will believe in you.

——Romain Rolland