Amateur Radio isn't only about radio. Speaking from experience, I've found that most people that get into this field don't just learn to operate a transceiver.
The technology gets you bit by bit and before you know it, the longer you've stayed in the field, the wider your knowledge and interest base has become.
You find yourself exposed to all facets of technology, including the expected electronics, mechanical engineering and physics sciences, however it doesn't stop there.
Because radio amateurs come from all walks of life and from all cultures, you also end up acquiring really diverse knowledge through the many varied conversations over the years.
The areas of amateur radio covered here are the mainstream technical areas of interest and only represent the tip of the iceberg. The deeper you look, the more that you'll find.