It seems unfair to attribute these things purely to talent. Especially in engineering, a weeder course isn't always that much more "difficult" but it is often a

It seems unfair to attribute these things purely to talent. Especially in engineering, a weeder course isn't always that much more "difficult" but it is often a lot more work. Anyone who has better things to do will do those instead. Working on genuinely interesting projects, working because you need to, having a social experience, throwing yourself into a hobby, whatever. Something that many students never realize is that taking a reduced courseload makes "hard" programs much more manageable. Especially if you want to spend time on things in your life outside of classes. Obviously, being "smart" or "good at school" makes you able to finish faster in the first place, but so does knowing the material beforehand. I knew a lot of students who'd done advanced classes in high school that cruised first year only to get their asses handed to them in second year when they had to actually learn material. And a lot of people leave engineering because they didn't know what engineering was or didnt really want to be engineers to begin with.