In the Exile on Princes Street foreword to Rebus: The Early Years, Rankin says he was living in London at the time of writing and didn't enjoy it, so "I brought Rebus to London so he could suffer, too".
In the Exile on Princes Street preface for Rebus: The Early Years, Rankin mentions living in London at the time of writing and found it unenjoyable, hence "I brought Rebus to London so he could suffer as well."