How does someone get to know thermal paste is a requirement without accidentally seeing how it’s required?

This is like knowing petrol is needed for your new car, then just stopping at some point, referring to the note “Get petrol” and deciding pumping it into every orifice the car has is what that means. “I assume that’s what that meant. I’m in a rush. No time to Google how to pump this “petrol” thing into the car.”