Oh I completely disagree about that - just because we don't all have them does not mean no-one does. A short sharp shock to the system can completely change the track of your life.
Sometimes there are moments that do change the direction of our lives - not necessarily even huge things but things that stick in our minds and inform our future choices.
The final point of the episode is one of the most valid ever made in Trek - that if you pull on one string the Tapestry of your life might fall apart.
The simple fact is ALL our experiences, good and bad, all our triumphs and all our mistakes make up who we are. If you go back and change one mistake you might make things better - but it is also possible in learning from that mistake you made much better decisions on more important things later.
