It is a given that to be an intriguing person, one must be able to inspire the perpetual curiosity of others  Constantly broadening one' s abilities and extending one' s intellectual reach will enable one to inspire that curiosity
If one's mind becomes impossible to fully comprehend, one will always be a mystery to others.
 For such a perpetual expansion of one' s mind makes it impossible to be fully comprehended, making one a constant mystery to others