Strenuous mental activity exhausts your resources, which you need to refuel afterwards (e.g. through taking breaks, doing nothing, watching television, eating snacks).
After a strenuous mental activity, your energy is depleted and you must rest to get it refuelled again.
When you have been working on a strenuous mental task, you feel energized and you are able to immediately start with another demanding activity.
Your mental stamina fuels itself. Even after strenuous mental exertion, you can continue doing more of it.
When you have completed a strenuous mental activity, you cannot start another activity immediately with the same concentration because you have to recover your mental energy again.
After a strenuous mental activity, you feel energized for further challenging activities.
Resisting temptations makes you feel more vulnerable to the next temptations that come along.
When situations accumulate that challenge you with temptations, it gets more and more difficult to resist the temptations.
If you have just resisted a strong temptation, you feel strengthened and you can withstand any new temptations.
It is particularly difficult to resist a temptation after resisting another temptation right before.
Resisting temptations activates your willpower and you become even better able to face new upcoming temptations.
Your capacity to resist temptations is not limited. Even after you have resisted a strong temptation you can control yourself right afterwards.