Kids aren't taught the rules today, but they never were (as numerous other posters have already stated). The difference today, in my experience, is that many kids are never even given the chance to learn how to cycle in the street, because parents are so afraid that their kids will get hurt. Instead of lack of parental supervison, which the OP criticizes, we actually have massive over-supervision. Most kids today will not be allowed the opportuniy to learn how by trial-and-error to cycle effectively, as most of us did.