Profound sadness, would be my answer.

On some primitive gut level you’d expect to be oddly satisfied by your own superiority, and amusedly angry at bad logic. But here’s what made me change my thinking pattern.

In college, I came across this (self-reportedly) highly-acclaimed web site of creationist science. On the front page, complete with pictures, were abstracts of young kids from a creationist science fair. There was this one girl, 6-8 year old, whose project was essentially this: She poured clean water into jars, prayed to God for six days not to create life, and at the end of six days she presented the jar as evidence against evolution. Her abstract was written with such moving sincerity, that it turned my stomach how anyone could do that to her.

EDIT: My memory of a house cat failed me (quite predictably). Thanks, David_Gerard. The blurb I actually read was most probably:

Patricia Lewis (grade 8) did an experiment to see if life can evolve from non-life. Patricia placed all the non-living ingredients of life - carbon (a charcoal briquet), purified water, and assorted minerals (a multi-vitamin) - into a sealed glass jar. The jar was left undisturbed, being exposed only to sunlight, for three weeks. (Patricia also prayed to God not to do anything miraculous during the course of the experiment, so as not to disqualify the findings.) No life evolved. This shows that life cannot come from non-life through natural processes.