Many years ago my dad went for his annual account review with the bank manager, back in the days when bank managers knew their customers individually and were the literal managers of their branch. He gave my father advice on his money, at which point my father said, "You're very good at this, your own finances must be in great shape"

The manager replied, "God no, I'm great with other people's money but I'm awful with my own."

It appears to be a truism that you don't have to have good personal behaviour to give good advice.