Ceilidh - or Kaylee, as she was known to her friends and anyone who had to write or type her name on a regular basis - did not consider herself a habitual drug user. She certainly used narcotics on a frequent basis, though she was quick to remind others that none of them were any more addictive than caffeine or cigarettes, which is to say, they were not habit-forming. Therefore, not a habitual drug user.
Her friends quickly learned that the point wasn't worth arguing.
