'm a big proponent of being in the NOW. Also known as being mindful or present.
The goal of being mindful is to be focused on life that is in front of our eyes; to do things deliberately and purposefully and not be distracted by our racing minds. If you think this doesn't affect you, or that you are 'good' at this, well, you are probably wrong. It takes real practice to have a fully aware presence of being all the time. Hell, the monks devote their entire lives to it.
"Meh, I'm sure it's easy if I just tried" says your skeptical-know-it-all-self.
Ok, try this: close your eyes and breathe in and out slowly for a minute. If you can successfully go that entire minute without thinking about anything in your outside life beyond just feeling the sensations of your breathing and being, than I apologize for my presumptions nature and please teach me your secret.
For the rest of us mortals, we will have to rely on meditation and mindfulness to quiet our hyper-active minds.
Meditation and mindfulness are amazing tools to help you with every aspect of your life. You can start small and progress your way into the practice. You aren't expected to be able to meditate for hours on end initially--nor is that necessary to see great benefit.
Case in point: I used to be a mega-worrier. I would worry about bills, appointments, speculation, other people, this, that, and so on. Then I found Buddhism and was introduced to the practice of being mindful--aka: in the present. This led me to finding meditation and Stoicism as I realized the power of mental training and pursued further study.
Now, after incorporating these practices into my daily life, I can honestly say that I no longer suffer from a chronic-worry frame of mind. I do stress from time to time but it's a fraction of what it used to be--again, thanks to these practices.