To be the best of my knowledge, and at least according to Chassidus, our life mission and life purpose are similar in that both of them are why we were born, and they are different in that the former is external, or a contribution we are supposed to make to the society and the world we live in, while the latter is internal, or a specific type of spiritual growth we are supposed to make.
I discovered my life mission at the age of 54 as a result of participating in group coaching based on Chassidus in Jerusalem from November 2017 until February 2018. This discovery was truly life-changing for me. It gave me a lot of material for contemplation, and eventually made me realize that academia wasn't even a means to fulfill my newly discovered life mission and decide to leave it on my own will for something that was in tune with this mission.
It was only two weeks ago during my weekly self-seclusion before the end of Sabbath. While walking and contemplating in nature in solitude, I suddently sensed two words intuitively - patience and compassion - and immediately realized that developing them is my life purpose in this reincarnation.
Since then I've been reviewing the major life events I've experienced and convinced that the more challenging they were, the more they contributed to the development of my patience and/or compassion.
When I discovered my life mission, all my life experiences started to make more sense. Now after discovering my life purpose, they make perfect sense. I also feel why I was guided to leave Israel after living there for 24 years and try a new life in a new location. I'm convinced that if I had remained in Israel, I couldn't have developed these spiritual virtues further significantly.