David Sternberg writes in his book, "How to Complete and Survive a Doctoral Dissertation," that the right reason to pursue a doctorate is a deep interest in your discipline, along with the intention to work professionally in it upon completion. I recommend this book to anyone having first or second thoughts about pursuing a Ph.D.

Social isolation helps if your intention is to get work done. In the words of the poet:

"Startups must be pursued for their own sake

and never to impress potential mates."