It is a truth universally acknowledged–that fact is stranger (and more wondrous) than fiction.
More than serendipity, more than coincidence or happenstance, a miracle is something that is not only beneficial, but also–depending on whether or not you believe in God–impossible. I'll explain. A Christian "miracle" is defined as a supernatural agency (God, the Holy Spirit, angels) working on the behalf of the recipient to produce a result or results that are intended to bless or better said recipient.
(Before I go any further, I would say that a lot of what we do and how we interact with others determines the quantity and quality of the miracles in our life.)
Back to defining miracles. (I'm going to call it a miracle for the sake of argument) A broader definition—whether one believes in God or not—says that miracles happen all the time. The question "why is there something rather than nothing?" (a rhetorical one?) is answered by appealing to the miraculous. As life is not inherently malefic, or miserable*, and it has more good than bad, the defining qualifier of inherent goodness means that life is a miracle. Do you follow my logic? Do you agree? Whether you take things at face value or not, the fact that there is something rather than nothing, and so many of those "somethings" (fresh blueberries, brown corduroy, the smell of honeysuckle, to name three) are so wonderful—that's the Latin root of 'miracle' by the way, wonder—makes life a miraculous and joyous thing to experience. And I would rather exist than not. Any beautiful thing that we experience, in order for it to have happened at all—from time immemorial, to the moment of experience—is a miracle. Think about it. And thank God for it, if you feel so inclined.
What do you do when you encounter people or events or gifts that are beautiful and unexpected? Does something resembling gratitude well up inside of you? If so, direct it to God. If you can't believe in God or if you don't think that He'd be responsible for the small graces that make life wonderful, then be sure to thank the people involved. And if gratitude finds no purchase in you at all, what's wrong?
Our vernacular overuses the word miracle. Or does it? Things like healing and deliverance and visions certainly fall under the miracle category, but so too, do things like desperately-needed job offers, unexpected checks in the mail, a break in the fever or a call from an estranged family member. The point is, we use the word "miracle" all the time but seldom do we realize just how right that label is. The things that God does for us are impossible to overestimate in value. And gratitude is certainly due Him and those (if any) He chooses to use.
"There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle." -Albert Einstein
*Misery is transitory. Beauty is forever.