LOS ANGELES Matthew McConaughey wasn’t lured to working on “Interstellar” by its cosmic story of space exploration to save all humankind. It wasn’t even that he would work with highly touted director Christopher Nolan or Oscar-winning actress Anne Hathaway.

He was drawn to the mega movie by the grounded nature of the role.

“I’ve been playing a lot of anti-heroes lately and while they’ve been good to me, I was more interested in playing the everyman of this film. And if you are everyman, then you are nobody in particular,” McConaughey says.

After his Oscar-winning role as the gaunt champion of the underdog in “Dallas Buyers Club” and his Emmy-nominated work as the emotionally scraggly police officer in “True Detective,” the one thing that attracted McConaughey to “Interstellar” was that he would be a farmer — and single father — who must leave his normal life behind to become a reluctant hero.

That hero pilots a spaceship through an artificially created wormhole in search of a new planet humans can call home. It’s a race against time as Earth is dying and because the young daughter he leaves behind will age far quicker than he will because of black hole variations on time.

McConaughey’s slow Texas drawl, lanky features and dry sense of humor gave him the kind of Gary Cooper-like characteristics that Nolan wanted for the role. The director was happy McConaughey was drawn to the film’s humanity and considers that the most important part of the film.

When the director read the first draft of the script, written by his brother Jonathan Nolan, what jumped out were the family relationships.

“We found that the more you explore the cosmic scale of things, the further out in the universe you went, the more the focus came down to who we are as a people,” Nolan says.

McConaughey’s connection to the family story comes naturally; he’s the father of three. His being an actor and having to be away from home for long stretches isn’t nearly as dramatic as what his “Interstellar” character faced. The actor points out that he’s been lucky enough with his career that he can take his family with him when he’s on the road.

But he could still understand the pain of separation.

“It was apparent this was about a parent and his child. That’s the aorta of the film emotionally. It’s the common denominator that everyone can understand,” McConaughey says.

Those connections became very important in a scene where McConaughey’s character must react to a series of video messages from home. He was worried about shooting the powerful scene because of having just spent the weekend away from the set doing promotional work for “The Dallas Buyers Club.”

McConaughy says the key to getting back into the role for that big moment was just to relax and not to try too hard. He was shown the pre-filmed video messages without a rehearsal and his initial reactions in the movie — what Nolan calls “manly man tears” — were from the first take of the scene.

“Interstellar” is the first film for McConaughey since he picked up his Oscar. Despite earning the highest honor the industry can give him, McConaughey is not taking any role lightly. He’s more obsessed than ever with the idea that acting is such a fickle industry that any role can be the actor’s last.

“The job that you are doing could be the last one. That’s a way to go into it. With respect to what has happened in the last few years, I have more obsession about what I’m doing at this moment,” McConaughey says. “It could be the last one. I hope it’s not. But it could be.”