Recently I met with someone who came to give a seminar and was sent their CV in advance and I was shocked to find that it was 107 pages, complete with table of contents and appendix. My first thought was "holy shit, I am so intimidated by this person, what am I even going to talk about". But then I read the CV. It really took me about a full 5 minutes before I could find this person's publications. It was a respectable publication record, but really not orders of magnitude better than my measly few, and for the most part large studies with lots of authors with this person's name somewhere in between, maybe a few case studies, MD sorts of stuff. There were hundreds of abstracts, including abstracts of all of this person's trainees, a shitload of talks, including stuff that I wouldn't have included, like small in-house talks or presentations within my working group (ie. lab meetings). Then it started listing every trainee, including high-school students and every single accomplishment of said trainees. Science fairs judged. List of journals for which they reviewed papers for, organized by year. And the more I read, the less and less impressed I was. It really was oozing with insecurity, and unnecessarily so because had the CV been paired down to its essentials, it would have been perfectly fine.
I find that this is a difficult lesson for many trainees to learn. There is a tendency to add as much as possible to one's academic CV, to try and sound as impressive as possible. By all means, I think it is super important to highlight one's accomplishments, but there is a fine line between tooting one's horn and sounding like a total douche.
Recently I came across this tweet:
And while I was a tad annoyed by its smugness, I do see the point. You don't want to present yourself in your CV in a way that makes it seem like your are something that you are not. So for example if the rest of the CV is filled with overinflated fluffernuttiness then listing your current position as "NSF predoctoral fellow" might come across as a tad douchey and put off a future employer. However, if you have a normal CV, then listing your title as say "NSF Graduate Research Fellow" might be fine, and highlight the fact that you received a prestigious fellowship.
So where does one draw the line? It's hard to tell. It's like what some Supreme Court dude once said when asked to define pornography, he said "I know it when I see it" (or something like that). It's the same thing with a CV. You have to look at it as a whole and see if the gestalt of it comes off as off-putting. Better yet ask a colleague, ask your PI (if you have one), ask your lab mates. And tell them to be brutally honest.