You're right about that. I lived in Hollywood for two stretches from '68--'84, first in Laurel Canyon, then in Hollywood on Cherokee Ave. You never knew who you'd run into.
I stood in line at the grocery story behind Jimmie "Dyn-o-mite" Walker of Good Times. Danny Kaye one time pulled up beside me in his limo to ask where the nearest pay phone was. I sat right next to Bob Hope and his manager in the next booth at Musso & Franks one night. Steve Landesberg was there as well.. Another night I was eating with a local video director. We noticed Roger Ebert sitting nearby. When he noticed my friend, he waved very warmly.
But my biggest thrill was meeting Muhammad Ali at Louie St. Pierre's Magic Shop on Hollywood Blvd. Ali was crazy about magic, so he'd stop into the store when he was in town. I saw Ali's 2-tone brown limo parked in front of the store in a no parking zone, so I walked in to check it out. Several people were wanting to shake his hand. When it was my turn, he stuck out his hand, and I shook it, but I was stumped for something to say, so I just said "You're the greatest". Dumb.