The trouble with writing humour is that it’s so subjective; lines that will have one person giggling up their sleeve will leave another completely unmoved. Consequently, many writers don’t even attempt it. Some say they don’t have sense of humour themselves, or that it’s just too difficult. I don’t write much humour myself, though I do like to inject sarcasm and understatement into my characters’ thoughts and dialogue. But conjuring up funny scenes is just beyond me.