Bill Murray might have carved out the perfect movie career. And it’s perfect in that it’s unexpected and quirky and always interesting. Like Murray himself.

He long ago gave up blockbuster fodder in favor of small roles or indie movies that intrigue him. (Murray famously has no agent or manager or publicist; folks interested in working with him leave a message on an 800 number, and, just maybe, he’ll return the call.) He makes the decisions — and the performances — look effortless.

The latest is “St. Vincent,” and while the plot sounds like well-trod territory — a curmudgeon has his life changed by becoming father figure to a child — Murray makes it feel fresh. He infuses his scenes with the boy, nicely played Jaeden Lieberher, with grudging fondness. He brings gravity and contained emotion to the scenes with Vincent’s wife, who has dementia and lives in a facility.

And, of course, he brings his deadpan humor to bear, particularly in scenes with Melissa McCarthy as the boy’s mother and Naomi Watts as a Russian prostitute.

It’s all a long way from “Meatballs,” my friends. Murray’s inimitable choice of movies has brought him, in recent years, from the laid-back naturalism of “Get Low” to the zombie-apocalypse kookiness of “Zombieland.” He’s become one of Wes Anderson’s favored players, starting with the wonderful “Rushmore” and popping up, even in cameo roles, right up to this year’s “Grand Budapest Hotel.” He dips into unexpected material, playing FDR — in a casting no one would have predicted — in “Hyde Park on Hudson” and portraying one of the men trying to save art treasures during WWII in “Monuments Men.”

Maybe Murray should advise all actors on how to conduct their careers. This might be the key: he clearly has fun choosing projects, and he has fun playing roles. Perhaps it’s no more complicated than that.