Generally, I believe there's no standard formula for success in life. However, there are are certain tested principles which we learn from people who have pass through the same path we follow and can use them as a guide in our own journey. Note it that this principles should only be used as a guide but not a formula. As individuals we are to develop our own unique approach, we can learn from the examples of others and mold them into our own unique approach for each situations.

what may have worked for us at one point in time under certain conditions, might not be suitable as those conditions change.

You are right, people need to be adaptive and flexible to be able to respond well to a variety or circumstances or be swallowed like the dinosaurs. One of the ways to improve on your adaptivity is to increase your scope of knowledge by learning new things in broad areas. I talked a lot about this in an article I posted about two weeks ago on my blog. Being knowledgeable and skillful in a broad area will increase your associative thinking ability which is a key to adaptation in changing environments.

combination of luck and a dedication to learn, practice and change behaviours as necessary to suit the environment.

You also talked about the role luck plays in our success and failures. It remind me of a verse I read once

I returned, and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favour to men of skill; but time and chance happeneth to them all - the Bible.

Thank you for sharing these words with us, I hope it will serve as a guide to most as we journey through life.