Of course physical attraction is important, love is part of that, but so much more. I know what kind of love you are refering to, not the mum or the cat kind. The soulmate kind of love does exist, but not all of us find it.
I don't want you to feel cynical about the whole thing, I truly believe that there is always someone for each of us that will make a difference in our lives, our best friend, our confidant, the person that will be there when we are down and doesn't make any judgements. The person you would do anything for and they would do anything for you, with complete unselfishness. The kind of person that can even bring a smile to your face when you feel in total despair. You know it is love when you feel this person with you, even when they may be miles away, you can feel their thoughts with you. The only way to describe is perhaps to say, "you are on the same wavelength". You are equals, you feel that you grow together. You don't choose to smile when you see them, you just can't stop the smile from coming.
No one is perfect, but when you meet someone and you feel that they are the most perfect person you have ever met, then just maybe, you have found your soulmate.