Some people think that you should try new things even if you know you will fail, for the sake of experience. I disagree. If you try something and fail, you will embarrass yourself! Plus, your failure could ruin your reputation, preventing you from getting more opportunities. Besides, if you try something and fail, you'll waste time that you could have spent on a better chance of success.

What is assumed when the claim $$you will waste time that you could have spent on endeavors you know you will succeed in if you try something and fail,$$ is used to support the conclusion that you should not try something if you know you will fail?

Wasting time that you could have spent succeeding would be morally wrong

You should not waste time on something you know will fail

You should not waste time and do anything that poses a significant risk of

Avoiding failure at all costs is more important than success

You should not waste time that you could have spent on endeavors with a better chance of success