Well...I have always pretty much been, "in shape," because I played sports growing up and was very active as a child. Even living in New York (by way of the Bronx) as a kid you could always find me climbing trees which later turned into pull ups and chin ups being one of my favorite exercises. I did not start working out seriously until 2009 when my parents surprised me with a year membership to Bally Total Fitness. I recall feeling like a kid on Christmas Eve because I could not sleep at all. I ended up waking up 5-6am the next day and went straight to the gym to, "test it out."
At that time I felt very comfortable with progressing myself weekly because I wrote down all my exercises on the back of a recycled envelope (what I do now) and recorded all my work in my computer's Microsoft excel spread sheet for record keeping. Back then and even now it always feels good to see progress over time and watch your sets, reps and amount of resistance used increase.
One of the trainers at the gym saw my envelope on the floor and asked me why I did, "random exercises," instead of lifting by body parts daily. It was then I was introduced to the whole: biceps/back - chest/triceps - legs/shoulders idea of working out. It was then when I noticed better improvements over time because I was also taking in my Pre-workout drinks - Whey Protein powders - BCAA's - and Glutamine.