"I was playing Rasputin and what was motivating him was crump..." — Tom Baker quote meaning

I was playing Rasputin and what was motivating him was crumpet really, and I was extremely keen on crumpet so I was really rather good as Rasputin. And my next catastrophic failure was Macbeth, who I played in the style of a crumpet-lover, and then when Doctor Who came along, I embraced this lunacy, this cloud-cuckoo-land where people had to be convinced by absolute nonsense. I came from a very religious background, so it was easy for me to believe in something I knew nothing about.