Significance of solving concave and convex problems

The antonym is frank and plain.

Basically, the road is uneven. The road of life is very difficult.

It means 1, and the road is uneven.

2, things are not smooth or unsatisfactory, metaphorically unsuccessful.

For example 1, the half-life is bumpy.

2. The road is rugged.

Life is hard.

Only on the bumpy road can you hone your mind.