Despite the general agreement that implementation of Enhanced Recovery After Surgery (ERAS) pathways decrease hospital length of stay, a continuous challenge that has often been neglected is a procedure- and patient-specific approach. For example, asking 'Why is the patient still in hospital?' is the original premise for ERAS. Outcomes improve with increased compliance with recommended elements, but overcomplication of pathways can lead to cherry picking of elements that are convenient, resulting in 'partial ERAS'. As there are few high-quality randomised clinical trials (RCTs) that evaluate the specific role of individual preoperative, intraoperative, and postoperative elements, challenges lie ahead to identify essential ERAS elements to facilitate more widespread implementation. To achieve this goal, the balance between large RCTs and smaller detailed hypothesis-generating observational studies needs to be addressed in order to enhance knowledge and limit waste of research resources.