Dhyana is further defined as 12 seconds of attention on an object (not much time to meditate), Dharana is defined as 12*12=144secs of attention on an object and Samadhi is 12*12*12=1728secs of attention, which is 28.8 minutes of total attention. This length of time isn’t too long and often, every one of us have found ourselves to have been in that state. When I totally engrossed in my work (and nothing else), I would have experienced Samadhi w/o realizing it.
Thus to meditate or experience Samadhi, you don’t have to sit on a mat in Padmasan. Yoga is a way of life and you can be an Yogi in whatever you do. Those who practice Hatha Yoga have a system that supports good physical and mental health and hence practice of Hatha Yoga should be an essential part of your daily life.
BTW, the ‘Power of Now’ is an account of total awareness, pick it up at your local library if you haven’t read it.