As a child, everything that happened or was expected of me required an answer to that simple question. I was definitely an annoying child but luckily I grew up with loving folks who tolerated my curious (and persistent) nature. Yet, for a very long time, being grown up meant losing my 'why' obsession. I think this had to do with the feeling that life was without purpose. Life seemed for a long time to be something to be endured.
Fortunately, in my mid-thirties, I regained a small share of that childhood curiosity. The documents, transcribed in 2016 beginning here, written in the late 1980s mostly, came about because of an obsession with knowing if life, my life in particular, had a purpose. I cannot imagine my life now without referring to the answer that came to me then and lives inside me.
In the video below Rabbi Simon Jacobson delves into the question of what gives life purpose and gives an answer that I can relate to very strongly. I particularly appreciate that while he approaches his attempt to answer that question from a Biblical scholar and Kabbalist's perspective, he shows great respect for the intelligence and background of his listener. As he quotes in his talk “the God you don't believe in, I don't believe in, too".