Even if there is an afterlife, why do we have an afterlife? Is there a purpose to an afterlife? Why isn't this life enough? Because we're not enjoying this one? Sometimes I think we're really concerned with these questions because we feel we're not allowed to enjoy this life. We're told our life belongs to something or someone else and not to us.
It's all about duty and purpose and what mom wants or God wants or your country wants or what your boss wants. You're supposed to be self sacrificing and help the homeless and starving people.
But if you take the attitude that you're here for just one thing, to make yourself happy and enjoy your life, your life belongs to you and you don't owe anybody anything, these questions aren't so important anymore. You can be satisfied with saying, "I don't know."