For me it is to:
experience everything you can,
learn,
teach,
create,
change,
explore your abilities,
help others to their greatest potential,
minimize harm to nature and fellow beings,
discover purpose for yourself and to help others discover theirs, foster community with your fellow human beings.
To be alive and aware of our surroundings through the senses. Use rational thought and common sense and respect each other. And also be free from dogma on every level.
One thing is that being human is our species and yes we are very unique, but every living thing is unique. I recognize humans as a life form that needs to recognize our relationship to all life and the planet, instead of the many who see us a special "creation." The difference between most free thinkers and religionists is that we know that the universe cares nothing about us and that we are no more important than any worm. So what is the meaning of life? What makes us human? To love, to learn, to explore, and recognize that we only have each other, making life an adventure that provides the opportunity for all of us to reach our full potential.
Live as fully as you can, not get caught up in the mundane, follow the golden rule.