Who said "I'm learning that trust is harder to build than speed."?

This quote is attributed to The Flash (DCEU).

I'm learning that trust is harder to build than speed. - The Flash (DCEU)

"I'm learning that trust is harder to build than speed."

The Flash (DCEU) Relationships

"I'm fast. Really fast."

"Time moves differently when you're moving at super speed."

"You gotta embrace what makes you different."

"Running away isn't always the answer, even when you're fast enough to do it."

"The key to a happy marriage is communication."

"Marriage is about compromise and understanding."

"Life's greatest treasures are relationships."

"Trust is a luxury I can't afford."