Everyone says when you find the one you'll know. The world will spin, birds will chirp, and a chorus will sing. Every wrong in your life will become right.
I think it's a bit more like this. Your world gets set on fire. That person infuriates you, but like a car crash- you can't look away.
Sure with them, the world is sunshine and rainbows and kittens- that's the honeymoon phase- it will fade.
Next comes real love. The arguing, the screaming, the sleepless nights- but don't worry you'll make up. This time, and maybe the next time too- if you're lucky.
Then comes the end. The defeat- the "just leave"- or "I can't do this anymore" The aching hole- tear stained pillows- wondering what in the world happened. "where did I go wrong?"
But don't worry- just as love fades, it will one day begin again. Take your time-grieve if needed, just keep your heart open.