This is more about building sufficient experience in something rather than being perfectly rational. For instance, think of the color green. You know green when

This is more about building sufficient experience in something rather than being perfectly rational. For instance, think of the color green. You know green when you see it. Why? Because of the numerous experiences you’ve had that have reinforced your knowledge of the color green. Such reinforcement applies to all your other experiences as well, including engineering. After some time, you should know whether or not you’re a good engineer without external validation.