During my undergrad I landed an internship at an investment bank that was highly sought after because the manager was an alumni who was legendary in his financial and managerial abilities. (His selection of me being the sole error in his otherwise flawless career I’m sure, but I digress). But the week that I arrived for the internship he joined another group in the company and I never saw him again. And the manager who replaced him? Well, let’s just say he a bit shy of legendary status.
I've made this mistake twice before - that of joining a job largely because of the chance to work with a great boss only to have him leave. Conversely I have also joined a couple jobs not knowing much about my supervisor only to find out that he is fantastic and an excellent mentor. This leads me to two conclusions:
1. I should never join a job just because the boss sounds like she/he will be great to work for.
2. I am lousy at predicting if my supervisor will be any good.
On #1, I've realized that as I get more experienced in my career it matters less who I work for as my performance is largely driven by me. Of course it's always nice to have a good boss and/or colleagues but your learning shifts from 3rd party observation to a larger portion of first-hand experience.
Of course, even if I had received the above career advice when I was in college I would probably have chased the job at the investment bank as it was a good bet at that stage in my career (and even today I'd totally work for Warren Buffet even if just for a day). However, I chase the "greats" much less these days - be it bosses or company brands - and look more for what impact I can make in whatever role I am in.