You get your hand prints on Hollywood's Walk of Fame simply by being famous. You get your footprints outside Grauman's Theater by being incredibly good at your craft. So phenomenally gifted an actress was Ali MacGraw that the theater gave her the honor after she'd appeared in only three movies. At one point, it was impossible for a film with McGraw in it to be bad. No matter how poor a script might be, she found ways to elevate it with her performance. Directors would probably still like to cast her now, but they can't - she's out of the business.
As she got older, MacGraw developed an interest in yoga to keep herself supple and stave off joint pain. The physical side of it helped her, but she developed more of an interest in the spiritual aspect than she was bargaining for. Yoga became her obsession, and she wanted to share it with others. That's why she turned her back on Hollywood and became a yoga teacher.