I have and have had many mentors ranging from "more generous than I could ever have imagined" to "this guy is stealing someone's air".
Pittfalls:
1) often, the ones who are offering mentorship have little to offer and are using the relationship to enhance their narcissism. I have never found a way out of this, without engaging some narcissistic rage. Yes, I realize the irony in putting this statement in some advice.
2) While your mentor is there is help you, this is motivated by a string of emotional reasons. Be wary, and assess what those are.
3) IME, there was a pull try to get in several opportunities that the mentor had created for him/herself and mentioned in passing. Like when friends order pizza in college, if you didn't chip in; it's bad form to ask if you can get in on that.
4) Due to the power differential, there is some paternalism/materalism. You are younger, asking for advice. They are going to talk to you like someone who needs advice.
Managing the transference is difficult. You want to be Freud or Ellis, not Ferenzi or Maultsby.
5) No matter how big of a name they are, the person is still just a guy (or girl version of that). Managing social interactions as peers is also difficult due to transferences, difference in life stations, etc.
Examples:
A) I had regularly scheduled dinner parties with colleagues 30 years my senior. PsyDr's GF did not like that one bit.
B) Several people I respect have made very "blue" comments to me.
6) You have to sit through a lot of stories. Some pointless, some on point.
7) They will expect you to know about them.
Attributes:
1) IME, looking at the mentor for personality characteristics and the mentor's lifestyle are very important. I.e., Find someone who lives how you would want to live in 30 years, and go after that.
Nuggets of Wisdom:
1) The neuropsych field is incredibly small and produces a lot of gossip. Be very careful what you say to ANYONE and what company you keep.
2) The ballers of the field, in research/forensic/clinical, are generally VERY busy. Respect their time by having specific questions, scenarios needing feedback, etc ready when meeting with them. While he/she is likely very nice, this is not social hour for them. Unless it is.
3) If you cannot repay their generosity, at least acknowledge it in real heartfelt expressions.
4) Be careful, some of these dudes are going to try to set you up with their daughters or granddaughters. It is such a bad idea.