It's good advice
When I was working we had to change passwords every 45 days so of course I had to write them down. Also you weren't allowed to have any dictionary words or permutations of dictionary words or numeric or alphabetic sequences or repetitions of the same character etc. It strikes me that the more rules you make the easier it becomes to crack the password by brute force, because so many combinations can be ruled out. You can discover the rules by trying to create or change a password because the system will tell you why your password can't be used!.
On the other hand I have a feww critical passwords which aren't recorded anywhere. I can remember them but it's very difficult if you're asked to enter the 7th, 12th and 15th characters for example. And they are completely meaningless character strings so there is no easy way to remember them. On the other hand knowing my interests isn't going help you.