List of basic reasons why you should wear a space helmet along with your pilot suit (especially if you are Machu):
>1. Don't let your identity get exposed.
>2. Keeps you breathing in case your cockpit gets breached or you need to exit in space.
>3. DON'T let your identity get exposed.
>4. Protects your head from bumping around when moving too fast in G-force
>5. DON'T. LET. YOUR. IDENTITY. GET. EXPOSED.
>6. Keeps your hair tightly away from your face better than, say, a loose wool beanie hat.
And many more to follow.