The new documentary “Elaine Stritch: Shoot Me” will leave you convinced that Elaine Stritch is the greatest person in the world.

Best known to today’s generation as Alec Baldwin’s mouthy mother on “30 Rock,” Stritch reminds you that she’s done a lot more than just that, thank you very much. One of the most renowned stage actresses of all time, Stritch is 88 years old and still working steadily. As she shows off her extreme confidence, wit and snark to the camera, doing and saying anything she pleases, Stritch will make you ashamed of your own life. She’ll make you wish you had even an ounce of the courage that runs through the bones of this “old lady.”

What Chiemi Karasawa conveys in her directorial debut is the belief that being old is something to be excited about, not something to be afraid of. Stritch seems to have stumbled upon some shocking secret — when you’re old, you can be who you want to be and do what you want to do, and nobody will judge you for it.

In one scene, Stritch stresses over whether she’ll remember her lines in an upcoming show. She comforts herself with this optimistic piece of advice: “If I forget my lines … fuck it.”

Still, as entertaining as Stritch may be, she is human. The documentary follows Stritch as she prepares for a four-week engagement of her show, “At Home at the Carlyle: Elaine Stritch Singin’ Sondheim … One Song at a Time,” at the Carlyle Hotel in New York. As Stritch prepares for the show, she also struggles with diabetes and alcoholism, along with, yes, the fear of forgetting her lines.

Stritch lost her husband John Bay in 1982, and in the film it is clear that she has developed a bittersweet sense of independence. She is surrounded by friends and loved ones — like longtime musical director Rob Bowman — but the viewer can feel the hole left by her late husband.

Regardless, Stritch takes on the world like a lion, embracing the stage as a lover and making friends wherever she goes. We watch as she messes around with the cast of “30 Rock,” teasing Tracy Morgan about the fact that they both have diabetes. The film contains interviews with Alec Baldwin and Tina Fey, and Baldwin even serves as executive producer.

Karasawa proves to be the perfect director for “Shoot Me.” Her film matches the boldness of her subject, maintaining a fast-paced, energetic vibe. Karasawa actually developed the idea for her documentary after encountering Stritch at a hair salon, and that perfect, beautiful spontaneity also runs through Stritch’s veins and the film itself. “Elaine Stritch: Shoot Me” introduces you to a star that has already been around for decades, and is one of the funniest films you will see at Tribeca.