I, too, had problems at first, but then I thought of the other side of "crybaby"--one who complains and whines over everything! I'm not sure "optimist" will always work, but I'm pretty sure that pollyanna will. To me, a pollyanna is one who always looks at everything in the most positive light (and always smiles). I find both crybabies and pollyannas to be incredibly annoying, so maybe that's why I lumped them together .
It's a bit difficult to come up with inquiries such as this when they are presented without any further context. So the most I would suggest would be words such as courageous, brave, valient, heroic, strong, rustic.
Hope this helps. If not, please give us some context to go by.