dashingscorpio, I agree with you to a point.
I think our lives are mostly the result of the choices and decisions we have made. There can be an element that is out of our control, and in the control of others' choices and decisions.
Like your friend example, we select our friends, but they must reciprocate. If they do not, no matter how hard we might want that person as a friend, they will not be a friend.
And, while I don't believe in destiny or fate, there still are things that can happen to us that we just can't control, although we do try. An example of this would be some kind of sickness or disease, like cancer or Alzheimer's. No matter who much we try to avoid them, they can still happen.
We do have a lot of control though. There are always options to improve, simplify, or otherwise change our lives and lifestyles through the decisions we make -- it just takes willpower and motivation.
So, I don't mean to nitpick, I just believe we don't always have complete control, but like I previously stated, I believe we do have a lot.