Because infinity isn't ours to worry about, or we'd go insane. Read some of Lovecraft's stories and you'll get the idea. What we do NOW, in the ONE life that we get, matters during that lifetime.
GUYS. HOW YOU LIVE YOUR LIFE REALLY DOESN’T MATTER. WE ARE ALL EVENTUALLY GOING TO DIE OUT WHEN THE UNIVERSE IS DESTROYED. ALL ACCOMPLISHMENTS YOU MAY THINK YOU EVER HAD WILL BE GONE AFTER A WHILE. RICH PEOPLE MAY THINK THEY ARE HOT STUFF RIGHT NOW BUT WHEN IT’S ALL OVER WE WILL ALL BE NOTHING IN A BOUNDLESS VOID. SO WHY BOTHER TRYING TO BE SUCCESSFUL?