You're young, and you will make your greatest impact later in your career.

While I'm not convinced what followed is bad advice, is this first sentence really true? I worked for 4 years with two different interdisciplinary teams of “distinguished” (aka late-career) scientists. They were all very accomplished, but the consensus of the group was that they felt the best work of their team was always done by grad students and postdocs. They saw their role as finding and guiding young scientists who were really doing the hard work of pushing the frontier of knowledge forward. I know I'm relying on anecdotal evidence, but from things I've read that appears to be a universal phenomenon in the hard sciences...