Need and want; the difference between love and like. The discrepancy between forever and the next five minutes that I feel like it.
To need is apart from desire. It is an emotional and physical imperative for functionality that must, by all and any means, be met. It doesn't alter or wane with the passage of time nor the development of danger. To need is to be vulnerable.
If you think about it, there really isn't much one needs in this world. It is perhaps just as well. With a certainty to the bare essentials of food, water and shelter, (by which our existence is assured), one can lead a life relatively unmarked with pain or disruption by not needing beyond these bounds. It is safe to need what is guaranteed to us.
Want, however, is without the opportunity for emotional turmoil, the possibility of disappointment or rejection. Thus, want flows with ones whim and fancy. You either get it or you don't and, either way, you've forgotten about it the very moment you find something new. Its effects are immediate, gratifying and short lived. To want is to use to ones advantage; to tailor to ones taste with alternatives. To want is to be in control. To want is be alone.
What if you decided you needed someone?
There is always the chance that someone might need you back...