I set up a simple program just to test how the code inside a get accessor executes (since I had been having some issues in another project), and found something quite strange:

class Program {
    static void Main(string[] args) {
        var test = new TestClass();
        var testBool = test.TestBool;
    }
}

public class TestClass {
    private bool _testBool = true;
    public bool TestBool {
        get {
            if (_testBool) {
                Console.WriteLine("true!");
            } else {
                Console.WriteLine("false! WTF!");
            }
            _testBool = false;
            return _testBool;
        }
    }
}

I expected the output to be

true!

But what I got instead was

true!

false! WTF!

Just what is going on here?