What am I?

Some small speck of dust
Simply to be swept away
Some buzzing fly pest
Swatted on a hot summer's day?

A piece of dirt beneath your foot
And you just keep walking
Just one inhale of your precious breath
But you just kept talking…

One smile on those Tantalus lips
In a life full of laughter
And on a windy fall day
But a breeze that follows after.