Tests and exams are there to ensure you have done the hard non-fun-stuff as well as the fun-stuff and to "prove" you have understood, not just regurgitating half-comprehended factoids. You are advocating the equivalent of a educational junk food diet, the only thing you'll absorb is the superficially interesting and the crap.

Serendipity has its place but if it is your principal approach then you are delusional.