From Michael Caine's 2018 book Blowing The Bloody Doors Off:
I just made Alfie and I was in Hollywood in the Beverly Hills Hotel with nothing to do. ... I used to sit in the lobby looking for movie stars and I spotted John Wayne.
He was registering in the hotel, and he looked at me, and said to me, 'What's your name kid?' I said, 'Michael Caine.' He said, 'You in that movie Alfie? You're going to be a star kid. But let me give you some advice. Talk low, talk slow and don't say too much.' And he looked down at my shoes, and I was wearing suede shoes, and he said, 'And never wear suede shoes.' I said, 'Why not?' He said, 'Because I just told you, you're going to be famous. And you're going to be taking a pee in the gent's toilet and the man next to you is going to recognize you, and turn, and he's going to pee all over your shoes, so don't wear suede shoes."