pgbovine nailed it. I learned this lesson from mathematics (I studied math in college and theoretical CS in grad school): the best math teachers always introduced a new concept/idea using a "toy" example. A toy example may not have the full generality of the overarching theory/idea, but it has all the essence without any of the abstract inaccessibility.
I try to apply the same lesson when I teach people data analysis: I learned (through my time as a quant on Wall Street) that a lot of people feel very comfortable in Excel but find other data analysis tools (SQL/R/Python) too abstract/scary. So, instead of telling them "Oh, you should use Pandas with Postgresql" or "that stuff can be done better using R", I show them what the equivalent operation looks like in Excel first, then show them how they can be done in SQL/R/Python (See, for example, this: http://blog.treasuredata.com/2014/12/05/learn-sql-by-calcula...)