When our oldest kids were two, I remember a mom asking me about "the terrible twos", and if Eason was acting up a lot recently, but he hadn't been. Later she showed me an article explaining the terrible twos, and why it was common behavior for two year olds who are having difficulty with the increased expectations that are placed on them relatively suddenly, because of their increased speech development.Having read this she was satisfied that this was normal behavior. I interpreted the article quite differently. My interpretation was that its never too early to start developing your child's coping skills.
When Eason was learning to walk I remember parents suggesting that there was no reason to push them since they would all learn to walk eventually, and they were right. Eventually they all learned to walk, and the ones who learned to walk first did not walk any better than the others. However, reflecting back, these were opportunities for children to learn the rewards of overcoming adversity. This is a foundation that can be built on with every hard-earned accomplishment.
Paul Tough talks about this on The Leonard Lopate Show where he discusses his book: How Children Succeed: Grit, Curiosity, and the Hidden Power of Character. What he refers to as "grit" I tend to think of as proactive and reactive coping skills.
He also touches on the limitations of standardized testing, as they lead to neglecting these skills that are better at determining success.