Mortal apathy
I believe that a period existed when my race times were very close to the times I would have run had my life literally depended on it.
Now, I don't think I could get to within 5 percent of my physical potential n anything longer than an 800-meter race even if my life did depend on it.
I often stand in such evil judgment of my own running -- when it comes to trying to do it capably, anyway -- that I often think it would be better to pay the ultimate price for half-assing it than face up to how slow I'm going to be for the rest of my life.
As much as I am enjoying running as a whole at the moment for all sorts of reasons, unless I can get past this serious hurdle (and I'm confident that I can, and that I know the path this will require), I shouldn't waste my money on entry fees anymore. I have enough damn T-shirts as it is.