3 things that boost self-confidence

Self-knowledge

Knowing yourself inside out will ensure there is no skeleton in your closet you don't already know. Nothing you face can possibly surprise or faze you.

Stability of mind

A well-controlled mind will allow you to command composure even in the most dire situations.

Self-recovery

Try to recover in five seconds, and your confidence will build. Over time, you'll realise nothing can get you down for more than five days!