Let's play this game again

your body still decays

...I mean, weren't the side effects already well-explored?

You can't die now, ever, not by accident, not by suicide. When you get bored of life, you cannot end it. You lose mental agility, collect all sorts of traumatic experiences, fall out with other people, and when they all die, you're still there - all alone, forever, in an unfriendly, cold, dark place, with no hopes to escape.

You experience the passage of time as ever increasing in speed, and before long the universe has died, leaving you --- immortal and sentient --- alone in the cold, dead cosmos, for eternity.