It's about feelings of isolation. Everywhere he goes he sees someone he desires to be with, but it never comes to fruition and he remains alone. Maybe the "darkness of the sun" refers to knowledge. The sun is often a symbol of knowledge, i.e. illumination, and the darkness of it is perhaps the knowledge that he is alone or will die alone. Or just in general knowledge often times brings a burden with it, the opposite of the saying "ignorance is bliss," wisdom is misery.
It's about feelings of isolation. Everywhere he goes he sees someone he desires to be with, but it never comes to fruition and he remains alone. Maybe the "darkness of the sun" refers to knowledge. The sun is often a symbol of knowledge, i.e. illumination, and the darkness of it is perhaps the knowledge that he is alone or will die alone. Or just in general knowledge often times brings a burden with it, the opposite of the saying "ignorance is bliss," wisdom is misery.