Do you “Hear” God?

I was talking with a friend of mine the other day about life. Particularly, we were discussing times in his life when he thought he heard God on a particular issue only to later find out that maybe he was wrong about that all along.
We started pulling past experiences from both our lives as examples of times when we were sure we heard God about something specific and then it came to pass. But we also had examples of times that we thought we heard God, but we were wrong; dead wrong.
As a Christian, one usually believes that God intervenes in our lives in various ways. Some Christians think they “hear” God all the time while others say we need only “hear” what is found in Scripture.
I personally believe that one can both “hear” and “see” God. Meaning that we can get an idea of what He wants us to do or what He wants to do in/through us then we can “see” the outcome of that.
But I am the first to admit, it is not an exact science. I have been wrong about what I thought God was saying or doing in my life almost as much as I have heard and seen correctly.
I think the formula is something like this…
One part peace / patience x prayer + obedience - pride = hearing God well
But to be honest, all parts of that equation can be a bit of a challenge. And sometimes it seems like even if you can master those things, there are still a lot of unknowns.
All this is complicated by the fact that sometimes we are “trying” to hear God but don’t really want to.
So what do you think?
Do you believe you can hear God? If so, How?
Why is there so much mystery in what God is saying? Is it our fault for not listening? Or his choice to keep things from us?