How to know which idea is the one?

Since my last film was finished I've written three feature screenplays but for whatever reason none of those are something that I want to make next- so I'm now starting on the 4th one that I will finish in a week-
Motivations change- things that excite you as a filmmaker change- I have to always ask myself "What am I saying with this film?" and "What do I want to say at this point in time?"
I'm over the thrill of the technical challenges, I'm over trying to prove something to myself, so now I can really get down to what is really important when choosing a film to make.
When you start any big project you're trading years of your life to realize the project- so you have to think about what is worth trading years of your life for...
What ideas or ideals are you willing to die for? 
What message do you think is so important you need to trade your life in order to make it real?
What topic can you not stop talking about?
If you always feel like you have more to say about a particular subject than maybe that is the one?
If I don't get choked up when running through a story outline I know its NOT the one because then it doesn't have a connection to my core and it NEEDS to have that if I'm going to fight for it to get made.Brought to you by professional weirdo M dot Strange.