I don't believe that drugs are the meaning of life. I do believe McKenna's stoned ape theory, which lends a fresh perspective to this question. Basically, what we now know as human intellect/consciousness developed as the result of millennia spent ingesting naturally occurring psychotropic substances, including mushrooms, on the plains of Africa and beyond.
We have now reached a point in time during which semi-synthetic and fully synthetic drugs have become commonplace. If one were to apply the basic tenets of McKenna's theory to man-made substances, there are some powerful and downright strange implications.
While I do not believe that any substance can be THE meaning of life, I feel that psychotropics can bring new meaning to life, and act as a driving force for psychological and sociological change. We are literally changing our own minds, becoming the only creature in existence to forward its evolution by its own devices.
In short, yes and no.
Oh you meant for humans! Egocentric, the world revolves around us humans?
Considering that we have dominated every other apex predator despite our relatively puny physical form, it could very well be said that the world has come to revolve around us.
I mean, dogs are a canine species so long domesticated that some breeds now lack basic survival instincts. Even the evolution of the primordial cockroach has been greatly effected by the presence of human beings, including their dependence upon our shelter, feeding, and waste disposal habits.
Don't sell us short, human beings are kind of a big deal.