I've had intense emotions my whole life, but I always put it down to being artistic/creative; the "artistic temperament" I guess, though that's a cliche and I don't suppose every creative person is the same and the arts probably have every personality description.
I feel things deeply, if something moves me I cry easily, if something is beautiful I have a lot of joy in it, etc. Even as a little child I was sensitive to everything, good and bad and inbetween, I noticed things and felt things about the things I noticed.
When I hit my teens and became hormonal, not surprisingly things got "worse" and I have never forgotten one night when I was agonizing to my mother about some situation I felt anxious about, my dad, overhearing, said to me "You're too intense. Why are you so intense? You shouldn't be so intense."
I took this as an insult and a judgement on who I was, because I couldn't freaking help it -- it was my personality. I was intense because the world felt intense to me.
That wasn't and isn't always ideal or enjoyable, but in my opinion it's also out of that intensity that I would begin to write a poem, begin a novel, write song lyrics, start composing music in my head and sit down at the piano to express it, or paint a picture. Those things didn't happen out of any time when I felt "eh, meh" -- they happened out of moments when I felt something about something, in a good or a bad way. So when he said that to me it felt like an attack on who I am. I know he didn't mean it that way but that's what it felt like. I've always been an emotional person, which doesn't preclude the ability for logic too, by the way.