The easy yes today is often a hard conversation next month.

Agreeing is the fastest way out of an uncomfortable moment, which is exactly why it gets chosen so often. The discomfort does not disappear; it gets postponed, gathers interest and comes back as a conversation where you have to walk something back and disappoint someone who was counting on you. The later version is always more expensive than the early no.

When a yes is forming before you have thought, buy yourself time instead. Say you will confirm tomorrow, then answer honestly once the pressure of the room is gone.