The ability to know how to behave correctly in any social situation is known in English by the Frnech phrase Savoir-faire, although it doesn’t actually mean the same thing in French.
When you lack Savoir-faire and feel uncomfortable in unfamiliar situations, it can drain your confidence. You feel unsure of yourself and start to panic and feel self-conscious.
But when you know the rules, understand how to behave, know how to make polite conversation, can decipher which knife and fork to use, you’re completely at ease.
This in turn translates into confidence. When you feel this confidence in every social situation, you’re said to have Savoir-faire.