Is the 'verb and subject number agreement' a hard-and-fast rule? Or is there some leeway?
For example, in the following sentences do I need to change the verb from 'was' to 'were' to match the subject number.
Change:
All that mattered was his dream and the boy that would help realize it.
to:
All that mattered were his dream and the boy that would help realize it.
And, change:
The first thing that sprang to mind as I watched Arpan walk out of the arrivals gate and look around the airport was the mad fervor that afflicted me about a decade ago and the boundless darkness that lurked in the two mountains.
to:
The first things that sprang to mind as I watched Arpan walk out of the arrivals gate and look around the airport were the mad fervor that afflicted me about a decade ago and the boundless darkness that lurked in the two mountains.
or:
What first sprang to mind as I watched him walk out of the arrivals gate and look around the airport were the mad fervor that afflicted me about a decade ago and the boundless darkness that lurked in the two mountains.
In the first example, I find nothing wrong with changing 'was' to 'were' but in the second example, I'm not comfortable using 'were' for some reason.