I think it is simply about Robbie's problem with depression and a propensity to say mean things (maybe even blasphemous?) when he is in that state of mind. In the lyrics, he blames Tourette's, which many think is synonymous with copralalia -- unintentional swearing. (In reality, it is an uncommon symptom of Tourette's Syndrome, affecting less than 10% of people with it.) I think he is telling us that he says things he shouldn't because of his depression and that while his bitter tongue is unpleasant for others, it is certainly no blast for him either.
I think it is simply about Robbie's problem with depression and a propensity to say mean things (maybe even blasphemous?) when he is in that state of mind. In the lyrics, he blames Tourette's, which many think is synonymous with copralalia -- unintentional swearing. (In reality, it is an uncommon symptom of Tourette's Syndrome, affecting less than 10% of people with it.) I think he is telling us that he says things he shouldn't because of his depression and that while his bitter tongue is unpleasant for others, it is certainly no blast for him either.