Flarepilot: "overthinking things can actually make a pilot neglect other things, like airspeed, or not hitting a mountain."
He was sitting at his computer when he asked the question, not flying round mountains. It's a perfectly good question (which you were kind enough to answer); the sort that students should ask and the rest of us benefit from by revising.
Different people have different learning styles. "Monkey see, monkey do" might work for some, but more intelligent students are far more likely to accept and retain information if it is based on understanding.
It is rather counter-intuitive that the same plane can apparently be flown faster safely when it is more heavily loaded.