"It's like having tons of tools in your garage..." Imagine that I am child playing with Lego blocks. There are 300 types of
blocks (300 TeX primitives) from which I am able to build everything what it
is possible to build from Lego. Each type of blocks has well know and good
defined feature. I am using these features _actively_ without reading of
manuals because there is only 300 types and I am able to remember them. On
the other hand there exists thousands of prepared Lego buildings (houses,
cars, boats, airplanes etc.), each of them includes hundreds pages of manual