A few sentences. Are there any mistakes?
It's difficult to know how we've become who we are now.
Thinking about it makes us conscious that the role of peril is very important.
It's easy to find many decisions, and some of them very important, that have completely changed the course of life.
Sometimes it was not a decision, but just a hazardous event that changed this course.
(Your English is very good, well done. My corrections are minor and I would be happy to explain them.)