Will you still be listening to pop or metal music when you're 80 years old?
>dick doesn't work
>ears don't work
>end up crashing your car into the front of a Denny's because you can't see shit and have your license rudely taken away
>everything hurts like hell
>ugly as fuck - even if your dick did still work, no women gonna have your smelly wrinkled old body
>doing basic tasks like showering/eating/dressing is a challenge
All this can be yours if you celebrate one birthday too many.
If you take care of your body and have some luck, you could perhaps live til 80 or even 90 without getting most of those problems. Also, the medicine industry is rapidly progressing and stuff like dementia might be curable in the future.