For me, Fi is the end test. Can I live with this decision? Does it feel right? I've always had the sense that once I've thought something through that I KNOW that I'm right (geez that sounds pompous) - but as I've gotten older, there is a caveat that creeps into my thinking ... but I could be wrong ... I've noticed that my Fi-filter has changed over time. There is still a strong degree of certainty to it, but it's not as rigid as it once was - it's just as strong, but more flexible.
So it's changed from:
Does it feel right? (to me) to
Does it feel correct? (not only to me, but in the interaction between you and me)
I'm much more open now to listening to the opinions and thoughts of people. In the past, I would have listened to them with the dismissive attitude in the back of my head that "even a blind squirrel can find a nut every once in a while". Now, I am much more likely to try to find something in them or what they are saying that connects with me, and in finding that, I am more likely to value their input. Instead of just focusing in on what's important to me, I want to hear what's important to you - I might find something useful in it and I'm open to hearing it. I'm also much more likely to admit that I was wrong and then reassess my judgments. That little voice that says "but I could be wrong" is always there in the back of my head now.
It's no longer about stubbornly having to be right. It's about being correct - finding a solution that benefits us both because that will help me make better decisions in the future.