Why are people so hung up with stereotype phrases like i love you?

the amount of questions you get on here like does he love me? how do i know if she loves me? he says he loves me but...? and so on...I dont understand this need for reurance we all have . I am romantic and i believe in the concept of true love but it is so easy to say this and then it goes to pot 3 years later. I have a friend of many years( yes a guy,lol) and i know he loves me and he knows i love him...we have slept together before and will do again but i moved away and even now we call when we think of each other,not when we expect to be called by the other and we know what makes other tick so well and we have told each other that whatever we have and whenever we have it we know its a forever thing between us...we are so close.i have been married twice, once to someone who professed to love me and was jealous and had a violent temper,that love didnt last long, the other again professing to love me but his conditions were too many, power freak!Why do these words mean so much?