Following a well-designed training program is useful and setting up a proper nutrition plan can make or break results, but there's one factor that's even more important and influences literally every single step you take towards your goal. It dictates how, when, and why you do everything.
That factor is: Understanding that working towards your goal is something you'll be doing for the next few decades, not the next few months.
Sixty-day programs to improve your squat and super-focused 30-day fat loss plans are awesome and can definitely be effective. Just know that you're not really anywhere near "done" when they're over because, whether you recognize it or not, training is a long-term game.
That's tough to remember in a time when social media minute-or-less videos are the norm and it appears that every guy "should" have striated delts and a 315 squat before they're of legal drinking age.
But strength doesn't develop overnight and impressive muscle doesn't appear in a couple of weeks. Knowing that you're in it for the long haul will influence your technique rep by rep and prevent you from testing maxes too often, pushing the high risk/low reward envelope.
It'll change your mindset from "I'mma slam a pre-workout and kill it in the gym. You only lift once!" to "I just finished a four-month block of solid workouts, hit steady PRs, didn't plateau, and feel good headed into the next phase."
Thinking about the long game will help you decide how to plan your next training phase and the one after that and the one after that, instead of jumping from one 4-week program to the next or, worse, training aimlessly just trying to "get bigger and stronger" (as if those were actual targets).
If you keep the idea in the back of your mind that you're still going to be lifting in the year 2050, it sets some eye-opening perspective that makes it the right choice to get 4 perfect reps instead of grinding out an ugly set of 6, and it means it's perfectly acceptable to never train the barbell flat bench press if you have bad shoulders.
So, it may suck to hear because immediate gratification feels nice and short-term thinking is a lot easier than long-term planning. But you know what's more motivating than watching some jacked, internet-famous 22-year old training hard in the gym? Being a jacked 62-year old training hard in the gym.