You are right,Sir! people have limited stores of self-control, or willpower, in any given day.Just like the money in your wallet, willpower is a finite resource that can't be used on one thing if it is already spent on another."When you use self-control for other things -- like meeting a deadline at work or resisting the temptation to eat a doughnut -- you deplete your pool of self-control," exercise scientist Kathleen Martin Ginis, PhD, of McMaster University tells WebMD. "We wanted to see how that impacted exercise.""The good news is self-control is like a muscle, and the more it is flexed the bigger it gets," she says. "The more you challenge yourself by doing things like resisting that chocolate cake or resisting the urge to hit the snooze button in the morning the more you build self-control."

Yes

I take jobs only if i am confident of fulfilling it

Have done it a number of times when i was working

It all depends upon how far you can stretch your talents and abilities to meet the demands of our job successfully and competently .

Not really .
The potential Energy is so vast
It keeps coming out when required blasting the inertia
The Mind always says not yet ...

Always in juridictions