Critical thinking. Logical reasoning leads to fearless exploration and in turn, creativity and innovation.
Problem hunting. It's preferable to solve painkiller-like problems over vitamin-like ones. But finding painkiller-like problems requires curiosity, observation and critical thinking.
Fearless learning. It takes courage to push beyond the comfort zone and learn the unfamiliar quickly.
Selling. Sell your works to your advisor, colleagues, conference/journal reviewers and thesis committee members.
Working independently. The luckiest PhD students meet with their advisors about once a week; the majority sit down with their advisors once a month. So a PhD need to independently take initiative, make plans, manage time, prioritize tasks, map research directions, look for resources, and actively ask for help when you need it.
https://medium.com/open-sourced-thoughts/phd-or-no-phd-d3dc89bc8e57