Danny Trejo had some sage advice when we caught up with him Wednesday afternoon at the L.A. Mission … no matter what, don’t lose hope.

The 81-year-old movie star chatted with us while volunteering to help families struggling this Thanksgiving. He says helping people has been key to his happiness.

He told us, “The more I can do for people, the better my life gets.”

He must have helped a boatload of people, because he’s doing fantastic. A source told us he had a knee replacement, and when we saw him Wednesday, he was walking around like he was 20 years younger.

Danny’s prescription for hard times even applies to people affected by recent ICE raids in the city, he told us.

“To the families … You know what? Keep up hope,” he said. “Help your neighbor and do whatever you can for people in need.”