A thesis is a powerful thing, I said

And just what is a thesis--and why does it matter that I have to do one for my assignment anyway?!

Glad you asked that question.  It's simple:  it's the reason, idea, point of explanation, or just "this is something that matters and I need to challenge and prove it" perspective of your assignment.  It's a fact--not an opinion.  (That matters a whole lot.  You need to establish a thesis as a condition of credibility.  Your opinion may count a whole bunch to you, but unless you are an expert in your field of study, don't bother trying to use your opinion to show your thesis has merit.)

I looked at the reason for my assignments in college through the view of my thesis: it was always based on "Why My Idea is Valid."  That's the thesis itself:  what is it that you want to teach to the person reading your assignment.  It's the heart-and-soul of your paper or presentation.  It's the idea or concept that gets right into your core because you KNOW this idea has a purpose or significance--and you want to show how important it is not only to you, but to the world.  Here's a view of a thesis:

Human sacrifice sounds like a cruel and barbaric way of behavior.  Children as well as adults of both genders have been victims.  However, the act itself has been practiced throughout cultures on every continent for thousands of years--and it has been glorified in the process.

It's not an opinion; it's one that I've taught with literature, so there are stories as well as documented history samples that I use.  What I do when I teach it is to use examples from various cultures (including the Bible!) to show that human sacrifice is not only accepted, but it is honored and revered.  

A thesis works well especially if it has some sort of "shock value" to it: the reader is awakened to a thought that he or she might not have considered.  (That, by the way, is what a Ph.D. degree involves: some larger-than-life idea that the candidate has proven by writing and researching; something that no one else has done or established.  The coursework involved frames out and supports the reasons for the thesis that comprises the heart of the candidate's doctoral plan.)

Here's another, based on the view that author Jonathan Swift was critical of the nature of Mankind:

Jonathan Swift, in creating the character of Lemuel Gulliver and his fantastic voyages, used satire to chastise the human race's views of superiority. Swift used direct social encounters with beings who were either tiny in size or as large as trees, the absent-mindedness and illusions of scientific experimentation, and finally, a reversal of intelligence within the family of higher mammals. In this way, Swift lets readers see the barbaric and grotesque qualities of Mankind. The voyages of Gulliver are a testimony in the ridicule of social roles to demonstrate the heights and depths of the potential of our species.

What students would do next (I wrote that thesis for them and encouraged them to use it) was to use examples from the book Gulliver's Travels and show in detail how and where Swift pointed out the flaws of humanity: our weaknesses, our failures as social creatures, and our downfall by our behavior. They would reference and give specific quotes as well as generalizations from the book, backing up the view that Swift indeed felt like humans were really a sub-standard species of animal.  

One last thing I learned about a thesis:  it makes for a great title of an assignment, and all assignments should have a title to them.  What I did was to take the thesis and then twist it into a question--and use THAT as the title.  For example, "Is Human Sacrifice a Barbaric Ritual or Sacred Gesture?"  Or, "Jonathan Swift's 'The Human Race': Noble Beings or Lowly Animal?" With either sample, I turned the thesis into my title by stating the main idea and challenging it.