Your life purpose is the thing that is in your heart, that you love most. It’s probably something (or related to something) that brought you joy as a child. The correlation may not be obvious at first – part of my life purpose is in helping people repattern their thoughts and behavior, so my genius lies in synthesizing information and pulling together a larger picture given just a few details… and as a kid I loved solving matrix logic puzzles.
Don’t listen to your ego telling you what you think you “should” be doing – that’s almost always going to be second best to what you really love. You serve best from a place of joy, because where your joy lies is where your genius is too.