The singer/songwriter and sometimes actor is 75, so you'll have to excuse him.
Asked how he first got to know Cesar Chavez, the iconic farm labor activist, Kristofferson says he doesn't exactly recall.
"We always had a close relationship," Kristofferson says. "He was a wonderful person. My wife told me we had him over for dinner. Like I say, my memory is horrible."
But this much Kristofferson knows, without question: He's a friend to United Farm Workers, the labor union co-founded by Chavez, and continues to help the organization through his concerts.
Saturday night, in fact, Kristofferson plays at Fresno's Warnors Theatre. It's one of six concerts he donated to United Farm Workers for its 50th anniversary.
He's not getting paid a dime -- not even for travel costs. All the money from ticket sales will go to the UFW.
"I've been working with United Farm Workers for about 30 years, maybe a little longer, ever since Chavez asked me. I could identify with the farmworkers because I grew up down in Brownsville, Texas. I was told I spoke Spanish before I spoke English."
So it makes sense that at Saturday's concert, Kristofferson will have two Latin opening acts -- singer Nydia Rojas and the group Trio Ellas.
In each city of his six-day UFW tour -- which starts Friday and wraps up the following Friday -- he is partnering with different Latin acts. They'll open up the concert before Kristofferson gets into his hits such as "Me and Bobby McGee," "Help Me Make It Through the Night" and "Sunday Morning Coming Down."
The series of shows takes him up and down the state, from San Diego to San Jose, but there is a definite emphasis in the San Joaquin Valley, with dates in Stockton and Bakersfield in addition to Fresno. And that's no accident.
"The San Joaquin Valley is the birthplace of the farmworker," says Tanis Ybarra, the special assistant to UFW president Arturo Rodriguez.
It was UFW, not Kristofferson, that picked the cities.
"I just go where they need me," Kristofferson says.
"For many years," Ybarra says, "Kris wore a necklace with the UFW eagle on it. There were some movies that he came in years ago where he was wearing a UFW T-shirt. He goes back a long ways.
"Having someone like him as a supporter means a lot, just because of who he is and the kind of people that he can reach."
Kristofferson worked in labor and construction before his music career took off, and he hasn't forgotten it.
"I empathize with the people who are trying to make a living," Kristofferson says. "I do a lot of charity gigs and I'm glad that I can bring funds into that that I believe in."
The reporter can be reached at(559) 441-6479, email@example.com or @mikeoz on Twitter. Read his blog at fresnobeehive.com.