The actor said:
I think we’d all agreed that Matt [Smith, previous Doctor Who] had been so wonderful and so delightful that the only thing you could do was to try and make a contrast with that.
Because Matt was so beloved and so open, I felt I had to be a bit more closed. I think Steven and myself had a hand in how far we could go with that.Capaldi stated he often tried to remove 'weepy' moments from scripts which may cause the audience to show affection towards his character.
He also admitted that the scheduling (working every day for eight months) was not easy and sometimes ideas simply dried up.