Grown-ups are mostly making it up as they go. They just have better poker faces and a mortgage.

Nobody graduates into certainty. The adults who look composed are improvising with more practice and higher stakes, and the calm you see is a skill they learned rather than knowledge they were given. Assuming everyone else received an instruction manual you missed is one of the loneliest mistakes available.

Ask an adult you trust about a decision they got wrong at your age. Most will tell you, and the answer usually dismantles the whole idea of arriving at a finished version of yourself. Then give yourself the same room to be unsure that you extend to everyone else.