I think passion is when you try something (theme A) for a good long period of time, and failed. Tried something else (theme B). Then when someone talked to you

I think passion is when you try something (theme A) for a good long period of time, and failed. Tried something else (theme B). Then when someone talked to you about Theme A randomly - and it struck you with a feeling on getting back into that field. <== then you found your passion. In your situation, you have no crunch time, no deadline. You sit safely in your good job (understood through the situation). But there is no urgency. Create self-motivation to try new things. Help people for free. If you enjoy the process even when its free - good opportunity to continue.