[PeterisP]

It's the same as with parenting - you can't really learn these things from people who've done this before, you have to learn them by doing it yourself. A large portion of potential parents put in a lot of effort to read up and learn stuff before their first child, but that's really nothing compared to what they can learn from actual experience; when rising your second/third/etc child, everything you'll use will be from the actual experience with previous children and just a minority of useful things will come from the initial vague guidance of others.

[mark-r]

I had a friend who was super excited to have his second child, because he'd be able to reuse the knowledge he had picked up with the first one. Then he discovered that his kids were polar opposites - he had to start over from square one.