You have a good point that these topics are not automatically argumentative as stated in this humorous format. To make these an argumentative essay, you need to think of the main persuasive point this topic will try to convince the reader about. In other words, the argument is the answer, or the list and how it humorously makes the reader realize the truth. For example, when you talk about "things my mom always says," you can make the argument that you should pay attention to these things because, even though what she says may be annoying or repetitive, she is often right. Alternatively, you could use this topic to say what you think moms ought to tell their kids, or what you plan to do differently when you parent (as a model for the reader, to argue what they should do too). With "how to annoy your roommate," you can use this topic to argue that a roommate shouldn't act that way or to persuade the reader that you have a good plan of how to get rid of a roommate they don't like.