First, I'm not looking for excuses for poor performance, and I don't want my kids doing that either. You screw up then own it. It's okay. You don't have to be perfect, no one is. But don't be a coward and hide from your own limitations.

Second, I think you're glossing over the part about process-oriented goals.

If one stays stuck on results-oriented goals, then your comment is pretty much on point. It doesn't matter who I'm competing with, I'll have bad days.

But with process-oriented goals, the focus switches how you do what you're doing, and that's something purely in your control.

To put it in exercise terms, you won't always be able to lift more than you did yesterday or run faster than you did 5 years ago--but you can always actually get off the coach and do it, you can always focus on your form, you can always push for that last rep or work hard into the last sprint.

It's really about an internal focus PLUS a process-oriented approach. Not just one or the other.