Contentment: the experience of satisfaction and being at ease in one's situation.
Sometimes, being single is nice. It's nice not to have to worry about all that hassle that comes with relationships. Not that being single means you don't have someone in mind, but the best kind of single is the kind with absolute contentment; you're not obsessing, you're not even really contemplating - you're just letting what happens, happen.
And so maybe you DO have an idea about someone.
That, however, does not mean you can't be content. If contentment is happiness with your situation in life, contentment with being single means you don't really know if things will happen with that person, or if it's even POSSIBLE for things to happen with that person, but you do know you're happy.
And how do you achieve this? By realizing that life is just a series of moments.
Years from now, you won't remember exactly how this person looks (unless, on the off chance things go really well, you've married them), and you won't remember the days you spent thinking of them, or the hours that you spent in their presence. What you will remember are certain moments that stood out; moments like a special smile just for you, or a joke told perfectly, or the sun on the bright green grass that the two of you sat on. These moments may have nothing to do with any romantic intention, but they'll stand out in their own, unique ways, and they'll bring you happiness.
Remembering this can help to put obsession and distress on a shelf that you never visit, and remind you that although things might not be the way you'd prefer them to be, they're still pretty damn awesome.
And if those moments will bring you happiness in the future, they'll bring it to you now, too.
Wishing you much contentment,