Roger that! I started out with Rocket Ship Galileo, and began to drift away somewhere around Farnham's Freehold. The early stuff, serialized in Boy's Life, was great stuff.
Same here...stopped for a while at Farnham's, didn't like it at all and it's the only Heinlein I never finished.
Just read hist real "first" novel and was astonished to find so many of his later themes.