Having titled it like that, let me tell you this up front. I've been to gyms and on a few occasions subscribed and lapsed out of the gym routine.
Gym is the school-model of staying fit. Go there, do the things in a particular manner, with the purpose of losing weight or gaining muscle (like getting maximum marks in school).
Some of the best times in school were when we played, when we whiled away time with classmates planning pranks or just chitchatting. While attending classes is what is considered important for career, the most pleasurable time was in all likelihood outside of the class.
Gym puts you in a class meant to get you a fit body. You don't make a career only through a school. You make it regardless. You make it coz something spurred your curiosity or interest or the desire to learn and earn. You don't stay fit just through a gym. You stay fit coz you enjoy your body move. You enjoy the freshness that the breathing fills your mind and body with. Fitness regimen would be more a result of the curiosity to explore the limits and stretches of your body. Not coz you have been made to undergo yet another class to shed a few kilos.