Where do we draw the line?

While in yoga today, towards the end before our Shavasana, our yoga instructor told us to bunch up into a tiny little ball and let everything that we had going on to dense up in that tiny ball and hold onto it really tight. After a couple of breaths we let it all go and simply laid there. She said that's the issue in our lives, that we simply let things drag along with us and we need to detach ourselves from them. That we need to detach ourselves from our past and focus on the present and that we should not worry about the future. That what matters the most is the day that we are currently living and what we decide to do with our love. What a thing to hear. Then I realized that maybe that was my issue with my life. I'm constantly focusing on what I'm going to do in the future that I hardly have time to focus on today. If not I keep referring to people as "ex-boyfriends" when well I think after a while they should no longer be referred to as "ex-boyfriends" but instead of old friends. It has a happier meaning to it and a more welcoming title to strangers or new romances. Same goes for old best friends. Instead of saying "she used to be my best friend" it's  best to say that they were my childhood friends. Life is a little better when you stop focusing on what you did in the past and what you want from the future and just realize that what you have today is what you have. So detach yourself from your past and realize that everyday you can start over.