The presenting of a gift to another has always been one of the most rewarding experiences in life throughout antiquity to today, especially when done without expectation.
In essence, giving is one form of the sharing of one's self with another. In so doing, we express our love, appreciation and perhaps random acts of kindness, whether there be an occasion or not. And it doesn't always have to be something so grandiose as the Taj Mahal ...
According to Homer, the concept of a duty to be kind and generous to your fellow beings was a force for social good, and helped maintain order.
Giving is a sign of grace expressed from one's life, bringing kindness even to strangers.