Many years ago I ran across a high school friend of mine who was just back from Viet Nam. We were sharing a pitcher of beer when he started hatching a scheme where we would both go home, get our rifles, meet on Conch Island, a strip of sand dunes off the coast of St. Augustine, and start hunting each other from opposite ends.
I told him I didn't want to kill him, he started telling me that he was too good for that to happen, started inferring that I was afraid to take him on.
To defuse the situation I just said, you're right, I'm scared.
He messed around for several years trying to get himself killed, jumping off of bridges, walking in front of cars. He may have finally succeeded, it's been years since I heard anything about him.
He probably didn't want to kill me, he wanted me to kill him.
That's a sad story. The moral of the Kyle incident is that head shrinking should be left to the pros. At the very least, you never want to turn your back on a potential head case who also happens to be armed.