A lot of problems work in the first ply but break down in the later plys.

In the first ply, you take an action and it causes a result.

In the next ply, the world responds, possibly adapting to what you did or fighting back.

If you only focus on the first ply, it seems easy. "Simply do the thing."

But the hard part is the second ply and beyond; constantly fighting back a problem that evolves as you interact with it.

If the second ply is hidden to you you'll feel like you're constantly getting unlucky breaks.

If you can see the second ply, you'll realize that things are fundamentally much harder than they see.