Concentrate on the muscle's action, the burn, the pump, the extension and contractions. This is not advanced thinking reserved for champions and pros. No time is too soon to think in these terms. If you're brand new in the gym, practicing your exercises with these obscure thoughts in mind will speed your progress. Always keep your eye on your goal, knowing you'll eventually achieve it and savor the time spent along the way.
Absence is erosive.
In fact, your presence in the gym can be restoring, even bring you out of depression, solve a problem, squash stress or inspire you to have the best workout of your life. Just go to the gym when all roads lead elsewhere, maybe nowhere. I've discovered new exercise angles, approaches and combinations on these very low energy, low spirited times out of simple instinct and survival. Basically, you'll want to settle into a sound exercise program for at least 6-8 weeks to provide your mind with order and discipline. It also provides time to understand each exercise separately and collectively and to afford the healthy overload to the muscles so they respond by growing strong.