Conceit is to nature what paint is to beauty; it is not only needless, but impairs what it would improve.

Self-promotion tends to reduce the thing it advertises. Real ability is visible on its own and needs no commentary, and the commentary itself becomes the first thing people notice, which crowds out what was actually there. Anyone who talks at length about how capable they are makes you watch for the gap rather than the work. The addition subtracts.

If you have done something good, let it stand without the explanatory frame around it. Say less than you could and let other people do the noticing, which they generally do.