Like most holidays, Valentine's Day can be either a good or a bad experience, depending on exactly where you are in your life. If you're in a good relationship, it can be a fine thing. If you're in a bad relationship, not so much. And if you're in no relationship at all, well...
I don't claim to have the answer to all things. But from observation, I see that being negative is usually a turnoff. (Not always. I know some couples where negativity is a way of life. But that's more unusual and not a type of relationship that I'd be comfortable in.)
I understand that being a optimist can occasionally get pretty tiring, especially when you feel like life is dumping on you. But if you've had a run of bad luck, things are about due to turn around, aren't they? (Let's not examine the converse.) And I also observe that a positive attitude is more likely to yield a positive result than a negative attitude.
So I choose to be an optimist. This doesn't mean that I won't have days when I get depressed or am just unhappy for one (good?) reason or another. It just means that I believe that things can and will get better and that what I do about it is going to make a difference.
Usually, it does.