It's the little things that make our days pleasant.
Sure, there comes along a huge occurrence that truly makes our day (or week/month/year/etc.), but what about the days between them? The days when nothing in particular makes our day?
Those are the days worth treasuring, because they're easy to forget. The big changes, they stick with us; we don't have to try to remember them.
God wants us to be happy, so He sends us flowers ("Consider the lilies of the field, how they grow: they neither toil nor spin, yet I tell you, even Solomon in all his glory was not arrayed like one of these.") every day. He wants us to be happy, so He sends us blue skies. He wants us happy, so He works through the words of friends, family, or strangers. He wants us happy, so He spends the day with us.
And more than that, He wants us happy, so He made us able to appreciate the flowers, the birds, the sounds, the skies, the beauty of His creation.
He pervades our day with little blessings, blessings we overlook, blessings we don't even comprehend or notice . . . And these things that we don't necessarily notice; they add up until they have made our day brilliant. And we don't even know why our day was wonderful. It's because God made it. It's because God put the beauty in it. It's because God was there.