The 2 hour test is recommended to be 2 hours after first bite, not 2 hours after finishing.
I have a cup of tea immediately following my meals, and after dinner I finish my glass of wine. Anything that raises blood glucose will affect the reading. That's fine if you just need to know your levels, but not so good if you are testing what the actual meal does to you.
By the way, there are no silly questions. (There may well be silly answers on occasions!!)