A long time ago in a galaxy far, far away (1958, Derby, UK in fact), Harry Morrow-Brown used his microscope from his medical school days to show that only those adults with airway disease and sputum eosinophilia responded to oral prednisolone [1], thus preventing this most powerful of medications being consigned to the asthma dustbin of history. Subsequent work led to steroid therapy moving from oral to inhaled [2], and thus nearly three decades ago came, not the dawning of the Age of Aquarius, but that of the age of inhaled corticosteroids (ICS). This age brought undoubted and huge benefits, and there can be no question but that low dose ICS when regularly and properly administered are one of the safest and most effective treatments in the respiratory armamentarium. However, in the aftermath of the discovery of a really effective treatment, instead of kicking on to the next stage, we have stagnated in an unsatisfactory comfort zone. Asthma diagnosis is inaccurate [3–5], but this does not matter, because ICS are so safe you may as well try them for any respiratory symptoms, and anyway, there is a big placebo effect. Medications are escalated uncritically, without thought as to why low doses are not working. Asthma mortality does remain unacceptably high [6], a red flag in our present morass of complacency. Finally, we get into sterile debates about whether, for example, survivors of pre-term birth have “asthma”. Crucially, we have lost sight of the great lesson taught to us by Dr Morrow-Brown, namely that all asthmas are not equal. The age of ICS, which started as the first use of personalised treatment, did not become the platform for building precision medicine, but instead, has reached an era of “put steroids in the tap water”, and writing and re-writing “evidence based guidelines”, which assume homogeneity and have signally failed to improve outcomes, while replacing serious thought about the problems.