As the saying goes, "a person's life is doomed, and it is useless to think about it." Is this statement reasonable?

This sentence has some merits, but there are also mistakes.

A person's life does have some destiny takes a hand's meaning. For example, you can't choose your parents and family. If you are born in a poor and ignorant family, it will really affect your life. But birth can't be changed, but fate can be changed through hard work, at least much better than not working hard. Although many people don't have a good background, they are optimistic, cheerful and willing to endure hardships, so they'd better realize the fate of counterattack. However, it is true that their success is more difficult than those with good families, but their efforts will always pay off, but the amount of return is really related to your luck.

But the last sentence of this sentence is more reasonable, and it is useless to think about it. For many things, thinking is useless. The most important thing is that thinking can't replace action, or you are an activist, then you will come up with better ways and means in thinking, so the most important thing is action.