Comment by bonoboTP

The capabilities needed for a phd are quite different from regular engineering college though. You can mostly pull through college using cognitive horsepower and hard work directed at obvious and explicitly defined things. Grad school (PhD) is much more about nebulous skills (in addition to hard work and smartness), taste, "reading the room" of the research community, networking, acting according to unwritten and unspoken conventions and "just knowing", branding, self-marketing, confidence etc.