As about one half of the human population harbour Candida species, the demystification of their conversion from commensalism to parasitism causing mucosal and systemic candidiasis would be of considerable value in the management of these ailments, especially in compromised population groups. Human candidiasis ranges from superficial infections of the oral and vaginal mucosae, to life threatening multi-organ systemic affections. My presentation describes how I attempted, over a period of three decades, to unveil the pathogenic mechanisms of an enemy that ‘sleeps with us‘ ordinarily, yet strikes with a vengeance given the opportunity. In brief, the data presented is a thumb sketch of various novel discoveries on the clinical epidemiology, aetiopathogenesis, and clinical management of oral candidal infections. Clinical epidemiological findings from various cohorts including diabetics, those on cytotoxic therapy, comatose patients, stroke sufferers, and from healthy individuals in three continents indicated that the previous data on oral candidal carriage rates in healthy humans of 40–60% derived essentially from the West cannot be extrapolated into Asia. Our findings indicate the prevalence rates are relatively low in healthy Asians ranging from 14% to 40%. With regard to aetiopathogenesis, candidal biofilm life style is now considered a crucial determining factor. A multitude of studies we conducted illustrate (i) how dietary carbohydrates modulate biofilms, and its clinical implications on the genesis of oral candidiasis, (ii) the conflicting role of whole saliva, serum, and sub-therapeutic concentrations of antifungals on yeast biofilms, (iii) the finding that the drug resistance of candidal biofilms is due to their intrinsic anti-oxidative capacities, and (iv) the role of indigenous oral bacteria in both inhibiting and fostering yeast biofilm development. With the advent of the HIV epidemic novel variants of oral candidiasis were described, throwing into disarray the conventional disease classification. Hence a new improved classification, that has now received worldwide acceptance was proposed, where the disease entities are principally categorised as primary and secondary oral candidiasis, with further new sub-divisions thereafter. An extensive enquiry into the oral manifestations of Asian and African cohorts with HIV disease highlights salivary defences and secondary oral diseases that may differ from Western populations. Other novel findings relevant to HIV infection that will be discussed include, (i) the identification of global sub-types of oral Candida albicans, (ii) the ultrastructure of pseudomembranous candidiasis (iii) increased Sap expression in C. albicans and, (iv) the enhanced avidity of Candida to buccal epithelium of HIV carriers. Management of the clinical variants of oral candidiasis poses new challenges and epidemiological surveys amongst both the young and the elderly in differing geographic locales indicate the relatively high, yet poorly managed disease. For instance, the dual, candidal-staphylococcal aetiology of angular cheilitis - an oft-ignored, peri-oral variant of candidiasis. In conclusion, this presentation redefines the clinical epidemiology, and the complex behavioural patterns of Candida species within the human oral habitat, that may lead to a deeper understanding of the prevention and management of mucosal candidal infections in general, and oral candidiasis, specifically.