I was at my parent's place the other weekend with the family and as usual my old Lego sets got pulled out.
It made me laugh looking at the directions that came with set 196 - "Building Set with People". My favorite image is the one of the horse with buggy.
I'm not sure when the more "custom" pieces started coming out (early 80s with the space sets?), but it certainly wasn't with set 196 in 1975.
Either way, my kids had fun using the old pieces to make a car / spaceship / plane.