Don't discuss yourself, for you are bound to lose; if you belittle yourself, you are believed; if you praise yourself, you are disbelieved.
Attributed to "Essais" by Michel de Montaigne, Book III, Ch. 8, 1595.

Don't discuss yourself, for you are bound to lose; if you belittle yourself, you are believed; if you praise yourself, you are disbelieved.