To some, unfortunately, nothing is worth any effort. These words will be incomprehensible to them. This is addressed to those who understand effort. The training in any martial art ranges from challenging to rigorous. Minor injuries are common.
Progress is slow and the attainment of reasonable competence can take years of study.
Finally, it can all be brought to nothing by the working of fate. Despite the frustrations, the sometimes glacial rate of progress, the pain, and the large commitment of time, there are those of us who believe that it is all worth it. Some want to learn to fight, others desire the comprehensive exercise, others need their confidence built, most want all the above. These are all starting reasons. Each physical skill has its counterpart in the maturing character.