The words you pick sound like something that would definitely work in a cowboy movie. Actually, I believe that ideal is used by a lot of resentful loners..... or Mai Valentine until she learned to accept friends.
T'is true, you'll likely need someone to "brighten up" your life someday. But the philosophy I refer to here is more something like "You're the only person you can (and must) fully count on and you're the only one able to lead yourself to your own hapiness." It maybe sounds a bit sad but that's something I happened to learn from life, often the hard way.
I understand that, honestly I can say I agree, and it's not sad at all because, in the moment you believe you're alone, that's a mistake, because we always have ourselves (: And knowing that, is enough, whatever that comes after, is a plus. We are the only ones who allow happiness or sadness overcome us, we accept the feelings aswell as we can reject them.