How do we not rue the many unchosen paths in life? A blessed lack of imagination. There are enough real glories along any path to swamp our meager ability to picture alternatives.
It is a rare man who can prevail in the face of comfort. Freedom is fragile and elusive, for rarely does the appreciation of it exceed the pleasure of being able to tell others what to do. There is but one tick on the accuracy scale between 'optimism' and 'denial.'
It seems quite proper to fear achievement, which, after all, is proof that you've successfully moved an experience from the delightfully anticipated future into the forever and sadly lost past. Avoid as long as you can the ultimate indignity: a lifetime achievement award.