I learned a little lesson again last weekend.
I was on my way home from Edmonton City Center (the closed airport) but that is another story, to Fort Vermilion 314nm north. Just north of Slave Lake I noticed my volt guage showing 11.95 volts and quickly came to the the conclusion I had lost my alternator. I began shutting stuff down and calculated I would have enough power in the battery to make it home.
That's one.
Without a radio I can no longer hear anyone in the area.
That's two.
I'm looking around in the cockpit figuring out how I'm going to play this when out of the corner of my eye I see a Canadair CL215 going in the opposite direction at my alltitude of 8500ft. He's about a mile away so not to serious but my first thought was, bastard, he's at the wrong alltitude. Because he is right beside me I can't judge his heading. Then I notice two more, a Convair and another CL on the same heading and descending just behind the first one. I'm heading 240, from their track I estimate they are on a heading of about 190, also in the west quadrant.

The lesson I took from that, well several lessons really, were just because you are at your proper alltitude you can still have a head on with another aircraft. A glancing blow from a CL215 is probably just as fatal as a full headon.
The other lesson is LOTFW!
That's only two, the third could have been luck, the rest of the flight I kept shifting around in my seat making sure the horseshoe was still firmly lodged up there.