One of the most persistent beginner instincts in Terraform is this:
“If I rearrange the blocks, it will work.”
That instinct comes from years of writing scripts.
Terraform is not a script.
Terraform does not execute top to bottom.
It does not care where a block appears in a file.
And it does not reward “clean ordering” with correct behavior.
Instead, Terraform builds an internal map of relationships.
What depends on what.
What must exist first.
What can happen in parallel.
When things break, the root cause is rarely order.
It is almost always a missing relationship.
A hard-coded value where a dependency should exist.
An assumption Terraform was never told about.
In this lesson, I walk through the mental model that explains why rearranging code feels helpful, but usually is not.
We focus on dependency thinking, identity flow, and the real risks that come from misunderstood parallelism.
If Terraform has ever surprised you, this lesson explains why.