You don't make me happy. You are my happiness. The difference between the two is simple, but important: You see, if you only made me happy, just the thought of you would be enough. A picture of you would suffice to keep me content. But it isn't. You are my happiness, embodied. So when you're away, my happiness is gone as well. Thoughts are not enough. I don't feel complete when I'm not with you. I need you. All of you. I can only hope that you need me, too.
I always thought of love like puzzle pieces. I know that metaphor's been done a hundred times over, but this is a little more specific. You see, everyone is built in a certain way. We are all pieces. Some people are whole pieces unto themselves - an entire picture, clear and beautiful. They don't need another puzzle piece. They're complete as they are, which is fine. Most people, however, are parts of a whole. They need other pieces to help them make sense, to see the whole picture. Some people have a lot of spaces and gaps, and it takes a lot of other puzzle pieces working together to keep them happy and to make them feel whole. Most people are halves. They are half of a picture, searching for the other half of themselves. However, these are puzzle pieces, meaning not every piece will fit with another. The pieces have to be the right size, the right shape, the right color. Puzzle pieces are complex and dynamic. Each one is special. Even if a piece is shaped really weird or has odd edges and angles, it fits perfectly with another piece somewhere. They just have to find each other. No one is wrong, and no one is unlovable. They just have to find the piece that complements them.
Somewhere, there is another puzzle piece out there that will help you make sense of yourself and see the whole picture of who you are. I always liked to think of it like that. I like to think that someday, someone as unique as I am will help me create a beautiful picture, a whole picture of myself, that we can both understand and be happy with. And I will do the same for them. Just like a puzzle.