It’s a fact of life: As we age, we develop lines and wrinkles on our faces (and other places). This happens due to a number of factors, some of which we can control to some degree, and some that we can’t.
One of those factors is the repetitive folding of skin due to everyday facial expressions. This is why we see perpetually unhappy people with “frown lines”, or by contrast, happy people who develop “laugh lines”. You really can see – to some extent, anyway – a person’s life experience literally written on their face!