Because it’s the closest thing to proof that people truly do live entirely different realities. Whoever you were staring at those shows at that age is simple not you now and can never be you again. It’s almost supernatural. If you follow this line of thinking, it’s possible to live entirely different existences, almost in another body (you can take that however far you want, reincarnation, life after death, being unplugged from the simulation, etc).

It’s a mystical way of asking “what exactly was the past really and how transient am I now at this exact moment?”.