As a professional photographer it can be difficult to remain passionate about photography 24/7 when it is both your passion and your career. I think Amateur photographers have it much easier as they only shoot when they feel the passion. It can be easy to get burnt out especially when you get overwhelmed with the non-shooting aspects of a photography business (updating social media, monthly accounts, SEO, emails, quotes, client queries etc).
If I am feeling flat and a bit jaded I find that one thing that always gets the Mojo back is to capture my kids. The best job in the world is not actually being a photographer; it is being a dad. I love my kids more than I thought it possible to love someone and spending time with them shooting is pretty special, especially knowing how fast they grow up and realising that each image I capture is a moment in time that one can never get back again. It is also a great way to sharpen your skills as you very rarely get a second chance to capture something so you need to be on the ball.