How do we know we have found "the one"?

Every time we start a love relationship a certain question pops out in our minds:"Is he/she the one I'm looking for?'' The answer is puzzling because there are no indicators to tell us:"run as fast as you can" or on the contrary "grab him/her and don't let go".And what if there are several "ones"? How do we know whom to pick? Of course that falling in love is the most important factor,but as the time goes by you may discover some tiny aspects that you don't like about her/him. Are they clear indicators that you should put an end to the relationship? If it were so,this would mean that "the one" you are looking for is perfect: he/she doesn't have any flaws,doesn't annoy you in any way,basically is the other you seen in the mirror.But now another question arises: Wouldn't it be too boring to live with another "yourself" for the rest of your life?

I know that you can say that I am haunted by too many questions but who can tell me which is the proper number of boyfriends or girlfriends in a person's life till she/he meets "the one"? I remember seeing a movie once where the leading actress was told by her mum that the 7-th boyfriend she will have will be "the one";nevertheless she felt the six-th was her significant other so she struggled to find a "replacer" for the sixth boyfriend.If you are wondering,her mother was right. So,boys,girls,7 boyfriends,7 girlfiends and here comes Prince Charming or The Sleeping Beauty?!

I will remain haunted by many questions related to this,but my strong advise is :"boys,girls,when you have butterflies in your stomach by simply seeing your better half,no matter how annoying sometimes he/she may be, I don't know if you have found "the one" but you have definetely found the big L.