Chit chat...

Last night, was chattin with 2 of my friends. One of them is a silly gal (just normal chit-chattin) and the other had some doubts about love. Same doubts that people generally get when proposed to by someone whom they do not love, or rather are yet to experience love in their lives.
1) How do I know if I am in love?
2) What does it feel like to be in love? (Tricky question)
3) I don't love him/her, but how do I convey that to him/her?
4) I love him/her. But how do I convey that to him/her?
5) Why do people fall in love? (Yup, people do get this doubt).

Now, I don't claim to be an expert in human psychology or in perceiving or realizing emotions and feelings, but my (along with some help from the internet and my biology books) answers would be,
1) If you are in love, you'd not ask that question. :) Yup. You will know you are in love when you are in love.
2) Well... this is quite tricky, since it depends and varies from one individual to another. This question is best answered by yourself, when you do fall in love.
(though not much of an answer, I hope people do agree that I am right. If not feel free to comment. :) ).
3,4) Be honest. Let the person know how you feel or what you feel. How he/she takes it is an entirely different matter. Remember, by telling the truth, you don't have to lose anything.
(Since, if you are in love with that person who proposed to you, you'd say yes and if you are not in love, you wouldn't propose to anyone, for the following explanation I am assuming, that if you are in love, you're the one who's gonna propose to and if you are not in love, then you are the one being proposed to.)
If you are in love, give it a try. This way you have 50% chance of success. But, if you don't do anything then you have a 0% chance of success.
Similarly, if you are not in love, let the person know about it immediately as you get to know about the matter.
5) Honestly, people fall in love, because, humans (actually almost all animals) are social animals. We all need a companion (though in animals, a companion normally keeps varying). We need love in all walks of life. Till adolescence, we crave for our parents' love. From then on till adulthood, we crave for love from our friends. Once we are adults, we crave for our partner's love. When we become a parent, we crave for our child's love. (It may be argued here that the love we want from our parents is different from what we want from our mate. Yes, it may be. But consequently, what your heart feels is the same.)
Hence, people during adulthood tend to fall in love. Of course, most of the times before/during/after adulthood, its just infatuation. But generally that is the age when people find the love of their lives (either after marriage or before marriage, but that's immaterial anyways).