I had a friend who had a big orange cat. In their kitchen there was a hole. One day, a mouse popped out of the hole like a Kitty Vending Machine.
Everyday for the next two years, that cat sat in front of the hole waiting for another mouse to come out. The owners felt so sad for the cat, they resorted to buying pet store mice to shove in the hole.
Over a month ago, there was a massive orange excavator ripping out trees at the end of our road. We took Baby Boy to see this and every morning since, at 6:30 am, he calls out, not for Mama or Dada, but "Truck! Orange! Truck! Trees!"
I walk him down there everyday to show him the truck isn't there...but today it was, like another mouse popping from the hole. His scream of ecstacy had neighbors running into their yard in a panic--there really isn't a better way to get to know your neighbors than having a toddler obsessed with machinery in their yard.
On the adult end of happy days: I went into my favorite bakery today and not only did I get a chocolate-seasalt cookie right out of the oven, but a customer was in there with two Maine coon kittens. If that doesn't make you smile, then you are a sourpuss.