You never know when this time will be the last time. Truly understanding that kind of permanence is very powerful and can have a profound impact on your life and the lives of those you encounter.
Simply treat each moment of each interaction as if it may be the last. You will become more cognizant and respectful of your time as well as the time of others. You will make sure that you take every opportunity to tell friends and loved ones how much you care. Your obligations will become conscious acts of kindness and respect. Insignificant confrontations will dwindle away. Grudges will vanish. Hatreds will fall aside. You will find yourself truly appreciating both your time alone and the time spent with others. Each and every moment will be a blessing. Each and every action, a willful gift to yourself and those around you.