"大きなことをしようとすると完全に失敗するのは難しい"

Simplified Meaning:

When you take on a big task or challenge, it's unlikely that you will fail entirely because even if you don’t succeed, you’ll still make some progress. Imagine you want to climb a very tall mountain. Even if you don’t reach the top, you’ll still climb a good distance and learn a lot on the way. For example, if you start a small business, you might not become rich, but you will gain valuable experience, meet new people, and perhaps make some money. Even if the business doesn’t fully succeed, you will learn lessons that can help you in the future. So, if you aim high and work on ambitious goals, you will achieve something worthwhile regardless of the final result. It encourages people to be bold and not be afraid of failing because they will always gain something valuable along the way.