Can someone be too optimistic?

Is there a right level of optimism in order to be a good optimist? I mean, I consider myself an optimist, the problem is I always have the highest hopes and than if things don't work out as expected I get disappointed and so I'm considered a pessimist. Or optimism means resignation? If you are content with less and don't even try to go for something bigger, of course you enjoy a fake satisfaction. But I don't want to see the half full part of a half empty glass, I want the glass to be full. What the hack, I don't want just the full glass, I want the bottle too. To come back to my question, can someone be too optimistic? Is wanting more the first sign of madness? I didn't ask for the galaxy, just for a fucking glass and a fucking bottle, so I don't think I'm being exaggerated.

Maybe optimism is not about hoping and wanting, but about working your ass out to get what you need. Optimism may be just another word for toil. If so, don't lie to me anymore. Don't tell me that having a smile on my face can help me go through all difficulties, don't tell me in the middle of the storm that good thoughts can stop the rain. Tell me that if I don't give up and I bear the rain, I might see a rainbow later. Or that if I find an umbrella I won't get wet.

It is said that you can do it if you think you can. Just be optimistic. No, that's just not enough. If you want something, even though maybe in your mind you believe that you'll never get it, you have to fight for it. And in the end if you fail, you are proud of yourself that you did your best. That's optimism.