I think you might have meant to ask, "When is the last time your reflected on life? - Not reflexed. But in answer to your question, I've been reflecting on my life all of my adult life and probably a bit before that. It is an ongoing thing with most people. Well, certainly with people who are inclined towards introspection.
There are, of course, many areas of our lives to reflect upon: Our relationships with others, or career prospects, our knowledge and wisdom, our health and fitness...many things. But it is when we start to reflect on such things as 'Why am I here?' 'Do I have a life purpose?' If i do, what is it? and how can I find out? And where do I stand in relation to the answers to these questions?
All things change, and continually change, including our views about our own selves. Keep asking those questions of yourself. You grow to be a very mature and wise person by doing so.