You can't succeed in science without mentors

Mentors are necessary for any type of career development (Where would you go if nobody recognized your talents and cultivated them?), but even more so in science where you need people to believe in you, give you money to develop your own ideas, trust your judgement and abilities, pretty much starting from the day you step into a lab as an undergraduate. A lot of effort is put by the NIH and other institutions to  have Mentored Career Development awards like the K99, K01, etc (see links, here), however mentoring is not uniform across laboratories and it is completely dependent on the Principal Investigator (PI). When you write a mentoring plan for one if these grants you have to describe a Utopian situation in which you constantly meet with your PI who will steadily guide you every step of the way through your projects, your papers and your career. In reality things can be quite different: your PI may not have time, may not be guiding type or only have insight on some aspects of what you do, and in the worst case scenario may actually undermine you. I have had my ups and downs, but I have been lucky (or picky) to have the mentors I needed for me at every step of my career. I've heard horror stories and wonderful stories from others.

I think the important thing is to always looks for mentors and to realize how important mentoring is. I know that people say that women always underestimate their own abilities and give credit to their circumstances without extolling their own achievements, BUT mentors were incredibly important in shaping my career trajectory. Every mentor had strengths and weaknesses, but there were multiple other mentors around me (colleagues, friends, other professors) I could rely on. While setting up my Individual Development Plan (myIDP, here), not only I had to think who my mentors are, but what they are for and it was a very interesting exercise. Instead of putting the burden of "full service" mentoring on only one person, it may be more effective to identify what each mentor is good at and use multiple mentors for all your needs. For example, a mentor for a specific part of a project, a mentor for departmental diplomacy, a mentor for grant writing, etc. As part of my K99 application I was requested to establish a Job Search Advisory Committee, a group of PIs young and older who would help me in shaping my application and navigate the interview process. Everyone of them contributed in a very important yet different way and I was a real eye-opener. Anyone can be a mentor even if just for 10 minutes, so started just asking any PI I meet for a piece or two of advice on how to set up a lab and got lots of great info.

The thing is that you will always need mentors: you will need letters from people for the rest of your life, for every career development grant application, for your tenure, for your promotion to full professor, for awards. My advice to graduate students is always that you should find at least a very strong mentor in your career, someone who will be there for you and support you and promote you and talk you off ledges whenever necessary. Having a good mentor makes your life much easier, but a lot of mentors are even better.