As kids, we dream of growing up. We think of what we want to be and sometimes forget to live in the moment and enjoy childhood. Then, when we are grown and we look back on less stressful times, we see lost moments of happiness that we spent focusing on the future.
Because of this, some people wish they could go back in time. Others even wish they could stop time. I understand what it's like to love certain moments in life and never want them to end, but those moments are special because they're fleeting. You could never fully appreciate the good times without experiencing the bad times. You need both to see the magnitude of each.
The passing of time is also one of the best things there is. Without it, you wouldn't be who you are today and you wouldn't have the opportunity to be the person you want to be tomorrow. You'd be stuck at a standstill, full of unused potential that will never be shown to anyone. I find that much more terrifying than continuing to grow up and learn.
Everything comes to an end, but that's not a bad thing. When something good ends, know that another good thing will come along. When you are in the midst of a bad time, know that that will end too. However, don't waste time thinking about the end.
"The knowledge of how much of a thing is left to consume or experience or be inside of or look at affects the enjoyment of that thing." -Andrew Schneider, Nervous/System
Don't lose yourself in worry; find yourself by living in every moment.
You don't have to forget the past or neglect preparing for the future, as long as you remember the importance of living in the present.