Although habitual residence would appear to be a ‘fact specific’ concept, the Court of Justice (CJEU) has increasingly interpreted habitual residence as a legal concept which links a person to the social security system of a specific Member State. Thus, for example, in Wencel, the CJEU ruled that a person could not have a habitual residence in two Member States at the same time. The Court has perhaps taken this approach to its most extreme lengths in the case of I where it has held that a man who had, due to illness, been ‘staying’ in Germany for 11 years was in fact habitually resident in Ireland. This note looks at this case – the first reference to the CJEU by the Republic of Ireland courts in relation to Regulation 883/2204 (formerly Regulation 1408/71) since Ireland’s accession.