1. it is part of your self-styled program of continuing education.
2. given current circumstances, this is as close as you can get to a social life.
3. a paucity of good conversation and worthy debators in your non-virtual social circle.
4. a desire to share knowledge and help others improve their understanding of science (or religion).
5. Its become a virtual addiction.
6. Something to do when drinking.
God does not "exist."---Paul Tillich, Christian theologian