A better phrase would be: "Don't do stupid shit twice".
Still better, in my opinion, is: "work on your weakness".
My hobby is Olympic weightlifting. In Oly lifting brute strength can take you only so far, to succeed and progress you need to constantly work on technique.
And the only way to improve technique is to identify something you're doing wrong at the moment and to break that habit. It takes time, effort and buckets of hard, horrible work; but at the end your performance has been consistently improved for good.
If on the other hand you stick only to what you're good at, you will inevitably peak. I am very good at back squats. If I'm not consciously trying to work my weaknesses, I will do buckets of back squats and get strong at them.
But what I ought to do instead is work on getting under the bar faster, or work on my second pull, or work on foot placement during the jerk, and so on. If I put the bulk of my effort into these, I will progress much faster and further overall than any amount of squatting will grant me.
Still better, in my opinion, is: "work on your weakness".
My hobby is Olympic weightlifting. In Oly lifting brute strength can take you only so far, to succeed and progress you need to constantly work on technique.
And the only way to improve technique is to identify something you're doing wrong at the moment and to break that habit. It takes time, effort and buckets of hard, horrible work; but at the end your performance has been consistently improved for good.
If on the other hand you stick only to what you're good at, you will inevitably peak. I am very good at back squats. If I'm not consciously trying to work my weaknesses, I will do buckets of back squats and get strong at them.
But what I ought to do instead is work on getting under the bar faster, or work on my second pull, or work on foot placement during the jerk, and so on. If I put the bulk of my effort into these, I will progress much faster and further overall than any amount of squatting will grant me.