Knowing when to push!

Am I the only person who deals with various mental and sometimes visual perceptions that you just must overcome or else you'll be derailed mentally and quit?
I thank God that the best gauge for measuring my success in the area of fitness are my clothes - granted during "that time of the month" it can tell an inaccurate tale, but overall my clothes lets me know when I'm on or off track. Plus picutres don't lie along with the measuring tape!!
On the days when I look into the mirror and lack seeing what I think I ought to see, I remind myself that I'm a work in progress. I didn't gain extra fat overnight, and it will take time, discipline and patiently enduring to see the end result.
Then on the days that I look and like what's visible I remind myself that healthy eating and exercise produces good rewarding results, and to achieve what I desire I must stay the course.
On the days when I have the edge and desire that overtakes me to push, I push with all my might. As was the case today - it was leg day and for 20 min with the exception of short stops for a quick squirt of water, I dug deep and pushed hard. Then completed my cardio with like intensity.
I learnt something from the attitude I had during my workout - what if I make the decision to do just that with every workout out - regardless if it is 10 or 40 min...regardless if I'm mentally exhausted or sleep deprived...what if I do that - will I arrive sooner at my finish line?
Well to find out, I gotta give it a try don't I?