Many of Slava's past articles have been written from the POV of "bitter experience", i.e. he made all these mistakes in the past, he deals with the consequences every day, and this is what he's learned from them. That's part of what makes them so valuable. I recall pg responding to one of them with something to the effect of "If you're founding a startup and don't understand the points he's making now, you will probably be making the mistakes he details in a year."