If weight training needs a more simplified approach in the modern era, it additionally needs a more intense attack. While I do not like how marketing approaches in this industry often uses the word “pain” to glamorize work, the grim reality is that for above average results you must push yourself in an area best called “discomfort”.
Psychological preparation will often change through the years. At one stage in your life, there will be yelling and screaming in your youth, followed years later with quiet resolve. From my vantage, the latter is the bite of the old dog on the porch where the former is the cute pup that a scratch behind the ears will calm.
Yet still the point of managing “discomfort” is a constant as to excel you must push were others drop. This requires a resolve to push onwards but an intense physical ability to maintain focus under duress as well as technical form. The latter two points are possibly the most concrete to visual as all training revolves around the ability to manage duress and perform with optimal efficiency.