Many people stop checking their shoe size once they reach a certain age. They figure that if they wore a size nine when they were 20, then that is going to be the correct shoe size for the rest of their life. The fact of the matter is that, much like the rest of your body, the size and shape of your feet is going to change as you get older.
Your feet may not grow as much as they did when you were a child or an adolescent, but the feet do continue to grow in length and width as you age. If a person is particularly active or they spend a lot of time on their feet, then they are probably going to grow even more.
With this fact in mind, you want to get your feet measured every time you go shopping for a new pair of shoes. Don’t insist that you must be the same size that you were ten years ago. If the size that you were wearing before starts to feel a little tight, trust the way that your feet feel and move up to another size.