Truthfully, many things. The death of my wife, the loss of my eye sight, the denial of the Faith by any one of my children (biological and spiritual), and any other number of things.
However, the question was recently raised as a comment on another blog, and the referent was my disallowance of comments on this blog. It is presumed that I don't allow them out of fear. Perhaps.
But my conscious intention was not to allow comments because I don't have the time to give them the attention they deserve. If someone takes the time to read what I write, and then write a comment, I feel I should give that comment the courtesy of a response. (I admit--I am awful at this even for the few who take the extra effort to email me directly.) So I have turned off the comment feature because, due to any number of factors, I simply have not had the time.
I also turned off the comment feature because, in a few cases, the interest was not to discuss or debate meaningfully the ideas presented, but to post a diatribe sometimes coupled with insinuation of evil motive. These I don't fear. But I simply will not take the time for these sorts of comments. Moreover, I also think it is spiritually unhealthy (for me and those so tempted) to permit the opportunity.
The result is that I write when I wish; and I opine about those liturgical and theological topics that interest me; and I do so not expecting anyone to read, but pleased when they do and flattered when it leads to a conversation elsewhere.