At the age of 44, I know I am middle-aged. I don't have a problem with this. It's only logical: middle-aged means you're roughly halfway through your life. In fact the next time someone tries to argue that being in our 40s -- or even late 30s -- is not middle-aged, I will say, "How long are you planning to live? Unless it's at least 110 years, you're middle-aged."