Who said "The work that matters most is often the most difficult."?

This quote is attributed to Doctor Erik Selvig.

The work that matters most is often the most difficult. - Doctor Erik Selvig

"The work that matters most is often the most difficult."

Doctor Erik Selvig Work

"The answers you seek are written in the stars."

"Science and magic are not so different when you truly understand them."

"Sometimes the greatest discoveries come from the most unexpected places."

"We must be willing to question everything we think we know."

"Hard work never killed anybody."

"Work with purpose and integrity."

"Hard work pays off in the end."

"A man's gotta do what a man's gotta do."