nature gives us an example, that this life requires a struggle.

Nature has its origin and end.
As said, starting from the sprinkling of spring that flows from the top of the mountain to form a river, upstream to downstream, and empties into the vast ocean.Certainly not apart from changes in mass, taste and color of water in every journey of its length.

That's the process of struggle.
No doubt as a human being, all interspersed by the process. Just like him in success, love and socialization.