Brief History: This is a philosophical Russian tale is about a Princess who literally never smiled. So her father declares that whoever can make her smile will be her husband (clearly, Dad just wanted her somber butt out of the house at that point). Meanwhile, a young working-class man suffered several years of bad luck which had been miraculously turned around by catfish, a mouse, and beetle whom he'd been kind to. While traveling near the castle, he was struck in awe of the princess who was watching him and fell in the mud. His animal buddies came to his rescue and the princess finally laughed. Seriously, imagine this for a moment. You see a fish flopping around on land with a little beetle and a little mouse, but all three are trying to help a grown man out of the mud. Yep. I'd laugh. So he marries her and they have a happy life. In other versions, she amused by the sight of him and his golden goose which causes all greedy people to stick to him, resulting in a conga line. In other versions, she breaks down laughing when she sees him struggling to carry a cow as a part of a promise he made. In 20th Century adaptations, the young man not only acts silly, but also tells the princess her own story which makes her realize just how silly she was as well.
Analysis: The main idea is usually that the man she falls for is not only funny, but kind. It's one of the few fairy tales where the princess ends up with a man who compliments her and makes up for something she was missing in her life. Also, her father seems to want her to be happy, not just use her for political gain. Sweet, but completely unrealistic.
Blame It on the Victorians: The 19th Century loved the German Golden Goose version better, which is probably the most ridiculous version of the tale. Apparently, the Victorians could only enjoy the story of a woman laughing if it was under the most absurd of circumstances. I'm not making bitter assumptions, I swear.
Last Thoughts: In Russia, smile never princesses