For the first time he realized the significance of the position.

She probably did not realize the significance of what had just happened, he thought.

It took a moment for her to realize the significance of what he held.

For a moment I did not realize the significance of this.

Only later had they realized the significance of that development.

Suddenly, for the first time, I realized the significance of his words.

It took me a moment to realize the significance of that.

"Not every officer would have realized the significance of what you saw."

I hadn't realized the significance of the date until now.

It wasn't as if he hadn't known about this test or realized its significance.