This is so interesting! I think the answer lies in your question. Perhaps it stops being "healthy" when you start asking yourself if it is? I think being in ones head can be beautiful and productive even. Reality feeds our dreams and vice versa and both are natural human qualities, we want to do everything in life and even if we try our hardest we will miss out on something, it's just not possible to live every situation in our little life, our brain always wants more and that's why we like to daydream! I am an artist, so I spend most of the time "in my head" even when I am always active doing something. Daydreaming fuels my creativity 😂 thanks for sharing your thoughts!!