This paper aims to improve understanding of the concept of practical wisdom. The theoretical lens used is Aristotle's practical rationality or 'phronesis'. Researchers argue that practical wisdom should be used as an organising framework for professional knowledge. Aristotle believed that practical wisdom as the highest intellectual virtue. Phronesis is the complicated interactions between general (theory) and practical (judgement). The contribution of this paper is to discuss the properties of practical wisdom and how they interact based on an interpretation of retirees' knowledge. The paper summarises in-depth face-to-face interviews with nine retirees, i.e., nine separate case studies. A structured interview guideline based on a conceptual framework derived from literature was used to examine the nature of retirees' practical wisdom. People with wisdom make better decisions. Whereas episteme's technical knowledge may address complicated tasks, techne's wisdom enables people to resolve truly complex tasks. Techne provides personal judgement which enables the professional to judge their actions from an external and internal perspective. Knowing that others and the individual themselves are happy with the quality of their work creates a morality that enables an inner calm and personal satisfaction leading to eudaimonia (feeling happy about life). People with wisdom behave differently. Phronesis's cognitive properties create awareness of the knowledge that may be trusted to be seen to be behaving normally or appropriately in the organisation. The global population is ageing. This has implications for future workforce planning as experience is lost and capability gaps emerge. Retires may represent a valuable source of knowledge to help address this gap. The results are limited to nine individual case studies and four disciplines. The findings provide exciting opportunities for further research. The conceptual models may be further investigated with retirees in other disciplines.