Being biased towards quitting your job is a great heuristic. Even if the boss is o.k., if you have any non-trivial reservations at all it's generally best to quit as quickly as possible. Probably the same for breakups. Very few people regret doing that, the most common regret is staying too long due to inertia, loyalty or whatever. I've quit 3 jobs and each time I wished that I had quit earlier, and all 3 times have been great for my career in the long-run.

If you were a good performer, you can probably just go back to same the job later if you change your mind as well, and if they don't want you back because they're being immature, then it's probably to your benefit not to return.