For me personally I have been doing what I love for the past 20 years. I am a pro basketball player. I am lucky to really have "job" I like and I am passionate about. Like in any other "job" there will be days where you don't feel like going to work, or doing anything. In my case practicing. But I do it anyway. Because like you said the team or company expect me to do my part. I have to keep in shape and work on my craft or my team-company will not be able to perform to the best of its ability. For me where I would draw the line if every single day I needed to force myself to do it. I stop becoming loyal to the game, and I am not giving my best every day whatever the it's a game or practice. But if we are completely passionate about something in order to progress we have to work for the "good days." I have been crazy about basketball for more than 20 years, and I know it sounds crazy, but I still become a little kid as soon as I bounce that ball of the floor. Anyway, that is my little take on it. Great article my friend. Have a great day. :)