[Skybird]

To find out how to come along in this life, and get along a way that hopefully is safer and more comfortable and less fearsome than others.

It's like with a boat whose captain got the order to sail to a distant point with some treacherous reef in the way. He must be careful, but no matter how careful he is, he never can gain an ultimate certainty:

He may get through, then all he knows is that the path he has chosen did work, but he does not know whether or not there is a shorter, safer passage, a more comfortable route available. All he knows is that he survived on the route he has choosen.

Or he sails into his doom, the reef damages and sinks his ship, and the captain looses crew, ship and his own life. then all he knows is that the course he has set did not pass beyond the obstacle. He does not know whether it did not fit by a huge or a small margin, and does not even know if there is any free passage through the reef at all. All he knows when dying is that the choice he made, did not earn him success.