Today is one of those days, where you just wake up and feel different. As a response, you say, "Oh, hello,   world. This is me." 
And so you get up, make a cup of black coffee, do school, and as my friend Carlotta says, play mom for the day. You help little sister with her spelling lesson, and think back to your own school and what you probably should be doing in retrospect but realize that this is where the here and now is at and you're perfectly fine with it. 
And you remember to dearly cherish these little moments, because in ten years, they won't be the little moments, they will (L-rd willing) be real life. I won't have the option to sing opera with sisters in the kitchen while making omelets for lunch and dance around for a school break. 
It's like that John Green quote that I've seen floating around too many times all over Pinterest: "One day you're seventeen and you're planning for someday. And then quietly, without you ever really noticing, someday is today. And then someday is yesterday. And this is your life."