The creation of a Thanksgiving meal is no small feat. The two things that make Thanksgiving dinner such an undertaking are the scale and variety of the meal. First of all, you're probably cooking for more people than you would for a meal with your spouse and 2.5 kids. Usually, extended family is involved, and their mouths must be fed. The variety of sides must provide when hosting Thanksgiving is of the utmost importance. If you don't have mashed potatoes, stuffing, cranberry sauce, green bean casserole, bread rolls, and pumpkin bread, you are not prepared in the slightest.
Those who are not used to preparing the Thanksgiving feast might find the amount of work that goes into it surprising, like the husband of a woman who has made Thanksgiving dinner for her extended family for 16 years in a row. When her husband offered to cook during a particularly busy year for her, she was happily surprised until she discovered what he was planning to make.