When I first started experimenting with KSP (I'm no kid at 33, BTW) I jumped into sandbox mode, then promptly pulled that 'woah' face you make when you go to a bar with a huge beer selection and the bartender asks what you want. I then decided that science mode was for me, to learn about how everything works. Then that got boring really quickly and I chose to consult YouTube masters like Scott Manley for tips instead. As an adult with a fairly good grasp of advanced technical concepts like orbital mechanics (and whatever else one must deal with in their chosen profession or their other interests outside work and KSP) it's sometimes hard to fathom just how much kids can learn in a relatively short period of time. We have to keep reminding ourselves that kid brains are massively fertile learning sponges, and they soak it all up without you even realising it. Take a ten-year-old for instance. They can read and write better than a lot of adults I know, so they speak the language, plus they're learning about mathematics, history, science, social skills, sports, politics, and society in general, plus more, all at the same time. Imagine cramming the same quantity of info into your head, and retaining a large fraction of it, over a ten year period on top of what you already know. You'd go bonkers.