I mean, there is def an applicable skill set there that most people won’t have. Understanding common passwords, the typical ways people might add variation to those passwords, and understanding how to apply relevant information about the person in question are all ways to massively narrow down the scope of potential passwords when brute forcing or guessing your way in. There’s a good numberphile video that covers something similar to this topic which goes into a bit more detail.

That’s to say: everyone should use a password manager.