But, really, have you ever loved someone so much it hurt? Scared you? Excited you?
Not love, no. I felt a strong infatuation though. I felt nervous, anxious, and scared; my initial reaction was to run, but I couldn't stop looking at them or listening in when other people mentioned them in conversation.
If so, why do some of us get so emotionally invested?
For me it was partially the mystery; I didn't really know him, and when I learned more about who he was and what he was like, I didn't really like him as much. Just, I guess, most of his physical traits interested me and gave me the impression that his personality fit my "ideal guy" because everything else looked promising. I guess we fall in love with love we feed the delusion more than... actual love is like.
Is it really a sign of weakness when you're willing to be submissive?
No, it's not. In a loving relationship, two people should be free to express their emotions and weaknesses openly. They should also treat eachother with kindness, respect, and warmth -- they should take care of one another. Part of that requires you to be humble to your partner and in some cases be "submissive" to what they need in order to keep them safe and well.
How come some of us calculate it like it's a math question and try to look for logical answer?
People don't like things like strong emotions; it scares them, so they try to rationalize it. It's part of self preservation; regardless of what you feel -- whether it's fear or love or hate or envy -- you become afraid of it when it becomes so strong you feel it controls you. If an emotion is so strong that it overpowers your rational thought, your personality, your human reason... you tend to lose sense of who you are and what identifies you. A logical answer at least gives you understanding of it; some people feel like it has to be them making the decision to feel that emotion in order to allow themselves to act on it. Some people see rationality as wisdom.
Is it really a emotion, or a chemical our bodies create and use as a unique way of finding a mate, just like animals do?
Your body is what allows you to interact with the world. It is what gives you information about it, about itself, and your brain is the thinking part of you. Without it, you wouldn't be anything. So yes, it's an involuntary emotion / arousal stimulus that is created by chemicals in the body so that your brain can receive and process that data in the first place.
Is "Love" real? If yes, explain why it is. If not, explain why it isn't.
"Of course this is in your head, Harry! But why would that ever mean it isn't real?"