I think there is a tendency for people to get rigid and caught up in their beliefs of what is right and wrong, and they lose sight of humanity. Being human has to come first before right or wrong.
Mistakes are a part of being human. Appreciate your mistakes for what they are: precious life lessons that can only be learned the hard way. Unless it's a fatal mistake, which, at least, others can learn from.
Challenging the meaning of life is the truest expression of the state of being human.
Studying whether there's life on Mars or studying how the universe began, there's something magical about pushing back the frontiers of knowledge. That's something that is almost part of being human, and I'm certain that will continue.
All the seven deadly sins are man's true nature. To be greedy. To be hateful. To have lust. Of course, you have to control them, but if you're made to feel guilty for being human, then you're going to be trapped in a never-ending sin-and-repent cycle that you can't escape from.