It may seem like a crazy idea to think always being happy can be sad. I'm not entirely happy with my life, but in recent years, it's been rather peaceful.
I'll have fits of anger and frustration and a little fear for some things, and some kind of anxiety, but overall I'm happy (on the outside). It may seem a little selfish to say I'm too happy, but it is.
For some odd reason, I have a need to feel extremely sad. I can't say why I have the need, but I do. Maybe I have the need to see others' sadness, but I can't explain what I'm feeling.
On a day-to-day basis, I'm generally happy. I don't argue with anyone, can't find a grudge, managed to control my anger, and usually forget anything negative after awhile. It seems selfish, I know, but the emotion I rarely experience is sadness, and it kills me.
An example is when I'm watching a movie. Movies where everything seems to have a happy ending, but at some point, it crumbles into a million little pieces. Somehow, I begin to feel complete. I pay so much attention to the details, I want to see it all fall at some point in the movie.
Another example is an anime with a sad ending. A lovable character dies of some cause and a crowd of people cry along with it. It's not the character's death that sends that odd yet satisfying chill down my spine, but the sight of the people crying. I can't decide if it's because I want to see sadness or it's my mind playing some crazy trick.
At times, I think if I were to hit my lowest point and do something to make others experience such sadness as mine, it would make me happy in the end. Others' sadness through some kind of loss makes my inner mind happy. I'm not happy at the moment, but the thought of others' sad state makes me have a certain feeling I don't think others would understand.
It's hard to explain what I feel, but I'll do it as best as I can.
Think of it as meeting your first love. The feeling of when they first hold, kiss, or see you. Now mix it with the feeling of fear. Anxiety-level fear, kind of like meeting someone new and you didn't plan for it. Now add a little bit of the end of a fit of anger from when your parents told you "no." That's what I feel when I see or experience sadness.
Somehow, this feeling makes me complete, as if I've reached every aspect of every emotion I can think of. It subconsciously makes me happy, although I already think I am.
Another (less descriptive) way I would explain this "feeling" is when something moves you. Not physically, but on a mental and emotional level. As if your mind is triggered and your heart slows down, but time moves on like you're in the past; an extremely happy moment in your life that makes it way into your train of thought.
Finding a Way
I can't fully explain the need I feel, but in the whole sense, it's sadness. On the outside, I'm generally happy. I joke and laugh, hate and provoke, run and avoid, and get disgusted every now and then. Sadness is an emotion I want but can't get unless it's around me.
Most likely if I experience extreme sadness and fall into a depression, it will suck. I've been depressed in the past, but under different circumstances.
Hopefully I can find an answer or some made-up medical diagnosis for why I feel this way, but my luck is starting to die down.