Aging will do that for some people, as will head trauma and other brain related issues, even an incomplete diet.
As others have said, it might be an indication of something more serious and worth paying attention to.
Honestly? The only things of value in a diet drink are the water and maybe the caffeine.
But as to the rest of that can full of chemistry? None for me, thanks. I quit! Almost anything is better than diet soda.
Coffee, for example, is much better for you. Mmmmm...fresh brewed, hot and delicious. Yum!
Plus, if you mix in some ground cocoa for even more antioxidants, and add some honey to taste if you like it sweeter, and you're doing your mind and body a favor.
Or go with tea if you don't like coffee, or just plain water...almost anything is better than diet soda.
No.
Everything else is fine.