The 36-year-old "Jurassic World" star shared the inspirational message while driving on an Atlanta freeway.
"I'm having fun. I'm overcome with joy and gratitude. I felt like posting this to say to anyone out there chasing your dream...
"Fifteen years ago I felt the same passion I feel today, but I had very little opportunity. I had to hustle hard and go hungry. I had to eat sardines and figure out how to get gas money. And I never had a plan B. I never stopped believing. Ever. Don't give up. Apply constant pressure for as long as it takes. It will break before you do. Go get it," Pratt wrote
"I did a table read for Guardians of the Galaxy 2 this morning and then shot all day on Passengers and just now wrapped some 144 hours later," he posted.