It's easy to be sad at being single.
It's one of those annoying little bugger facts. Of course, it's great somedays. Certainly, when I see my friends going through what appears as useless drama, I heave a sigh of relief that it's not me. Ha. Then again, I look at my friends holding hands with their loved one and am slightly jealous of their love.
But I don't think singleness should ever be something we're sad about. Nor do I think it is a) appropriate to consume oneself in searching out a partner, or b) necessary or productive to try to find fulfillment in someone else. Ultimately, you'll always be stuck with the same problems you had without that extra person's problems now in your life. Deal with those before you go searching out the problems of someone else.
Singleness can be grand - you have an independence to your life. No strings attached, you can travel and make choices and be free to do as you please without consulting your partner. And indeed, many of the greats of our generation have been single, and for a good reason. It's hard to devote your life to both another person and to a cause you're going to put your everything into. And so we must be cautious in pursuing relationships, so as not to forget that time is the key to success. Both with relationships, and in our work, whether it be school, volunteer, or employment.
And yet, all this to be said, I do believe that there are times when we moreorless 'fall in love.' When it's quite clear what your feelings are towards someone, when those don't change, and when it's all but apparent that you would be happier with that person than without them. And at that point, I say pursue them. Perhaps, in this case, you can have a truly fruitful partnership of marriage, and it is clear that two is better than one. Definitely, living life with a friend is better than by yourself. Even if singleness is often easier.
And thus ends my rant. Not that I've said anything new. Just garbling down thoughts. :)