So what IS a thesis?

"She called me at 1 in the morning to ask me, 'What's a thesis?'"

The speaker is one of my students, and "she" is another. The first major paper is due in five minutes. The students had read a chapter on writing a thesis statement and I had talked about thesis statements in class, demonstrated how to formulate thesis statements for this type of paper, and offered specific suggestions for improving their thesis statements in my comments on their drafts. Also, last Friday I reminded the class that I would be happy to look at revised thesis statements over the weekend if they would e-mail them to me. Two students did--but not the girl who had to call her classmate at 1 a.m. to ask "What's a thesis?"

Sometimes I wonder why I even open my mouth.