There are a number of mental attributes a person needs in order to fulfil their physical potential. Motivation, intelligence, resilience will all come into play, but unlike measuring how much weight is on the bar, it's very hard to accurately assess how much of each attribute a person has. Luckily in much the same way you can become bigger or stronger, you can become more motivated, smarter and mentally tougher, as your exercise journey continues so will your mental evolution, whether you like it or not.
Motivation
This comes a lot more easily for some than others. Motivation is nothing more than the desire to achieve something and the willingness to do what it takes to reach that goal. A lot of people know what they want, it's the action where they fall short. The key to maximising motivation is to set small goals on the way to a bigger goal. If you want to have arms like Phil Heath (I hear ya) then you should set a goal to add 1cm to the guns in three months. Next stage is to put together a meaningful plan which should help you get there. Now execute. Once you've followed through and your arms are bigger you will be not only one step closer physically but one step closer mentally. Success breeds success. You know if you apply energy and effort you will reap the rewards. Seeing a change in your body makes you want more, it feeds your motivation. Don't stop, set a new goal.
Intelligence
I often see my extremely motivated clients fall down here, not because they aren't book smart, or can't hold down high pressure jobs, but because their passion and drive can blind them to the signals there body is sending them. I'm not talking academia here, I'm talking about an intuitive ability to read their body, or perhaps it would be better labelled physical wisdom. I've had clients try to train through minor injuries and make them major. I've had clients force feed themselves to the point of digestive breakdown. I've known hundreds of people over the years that have seen progress with one form of training so they have persisted with it in the belief that it is the correct way to train despite it not working anymore, often pushing harder and harder, until they regress or get hurt.
Everyone no matter how genetically gifted is best served to listen to their body, to monitor it and how the ways you train and eat affect it. Knowing when to back off, or when to totally change tacts will be of great benefit to any athlete. How do you master this? Well if you're like me, you train through minor injuries until they are major, you force feed to the point of digestive breakdown and you persist with programs until they break you. Trust me no matter how thick headed you are you'll get there in time, just try not to learn each lesson more than once!
Resilience
This is the big one in my eyes. You simply cannot control all external variables. Life will throw curveballs at you that make your goals more difficult to reach. Resilience means you'll push on and make the best of that situation regardless. If you have elbow tendonitis you don't need to stop training for three months while you wait for it to recover. Sure it may not be as much fun brutalising the Pec Dec instead of pressing 180kgs, but it will be a lot more beneficial for your chest development than not training at all. If you're not training legs because of your elbow tendonitis then what the hell are you doing! The most resilient people, especially those with some physical wisdom can find ways to train around all sorts of debilitating injuries. If you've recently started a new high stress job and you're mentally exhausted. It's okay that you don't have the energy to set a squat PB, but if you get yourself in there and do something, even if the weights are merely a form of therapy and at best maintenance, you are a few rungs up the ladder from those that gave up on the gym until they could cope. You won't always be your absolute best, but there is no reason you can't give it your best under your current circumstances, that's what resilient people do.
Resilience like the other mental attributes is a product of experience, make yourself go to the gym just once and you'll know it made you feel better, even in some minor way, keep going and the benefits are cumulative, you'll be tougher mentally and physically.** The best advice I can give anyone who wants a crash course on the mental aspects of the bodybuilding game is this. Pick a competition and compete in it. You want motivation, how about the thought of standing in front of hundreds of people in hardly any clothes. You want to get in tune with your body, I can guarantee you one contest prep will see you be inundated with a series of messages so loud and clear anyone could decipher them. Granted the last few weeks the over riding message may be to eat cake, but I can guarantee you will know your body like never before if you make it to the stage. As for resilience after a contest prep you will realise how easy you've had it all along. You will have a new found mastery of time management and you will couple this will the knowledge that you can push your body further than you ever imagined possible. With all the federations and divisions available these days regardless of your current condition the chances are you could be onstage battling for a placing within the year. Go for it.