Companion is a form of mirrored compassion. Walk together, side by side. And world are full of wonderful companion.
Then again, companion is not a must - at least for me in my humble and narrow point of view. To walk around by one self is always an option that we can take. Who said people can't sail by them selves alone.
Perhaps you have a place where you want to go. And you can't take someone on your journey while that someone wants you to settle down. You can't settle down either when your companion wish for a journey, except both of you are okay not to stand and walk side by side, are okay just to reach some point of this life together, and then go to each of your own destination.
Well, that just about this life. Nothing is an absolute must for each of every of you. If you ever find someone said to you that you have to had a companion or the opposite which is to walk alone; you know what to answer.
If I chose to walk alone, the be it, otherwise ... you know what I mean.