When my kids were very little (crawling stage), I found places with maybe 2-4 steps for them to climb.  They learned what happened when you fell or misjudged steps, but they did so in a situation where they would be scared and maybe even get a little scrape or bruise, but they couldn't be seriously injured.  This enabled them to learn consequences without the consequences being too bad.  

Unfortunately most parents today protect their kids from experiencing consequences of their actions.  When they become adults, they can't see the consequences of their actions.  Also, as adults, the consequences tend to be much more severe.  Parents overprotecting their kids leads to their adult progeny suffering 10 or a 100 times more when they experience true consequences.  Unfortunately, they aren't the only ones suffering from the bad parenting.  We all pay the price.