How would you describe cycling as a hobby?

How would you encapsulate the essence of cycling as a leisurely activity? Is it purely a physical exercise, or does it encompass mental and emotional benefits as well? How does cycling compare to other hobbies in terms of accessibility, cost, and social interaction? Furthermore, what specific skills or knowledge does one need to acquire to fully enjoy cycling as a hobby? Lastly, what are some of the most rewarding experiences that cycling as a hobby can offer?