Computational modelling of biomechanical systems has experienced exponential growth over the last two decades (of the authors academic career at least). Technological advancements in medical imaging and computational power has fuelled this growth and we are at an interesting cross-roads, where the traditional methods of biological and clinical science are giving way to disciplines of mathematics and engineering in order to further our understanding of biological systems and the form-function relationship of our musculoskeletal system. Few would argue the impact that mathematical modelling and engineering disciplines has had on our lives when they happily travel to the other side of the planet (pre-COVID) on an airplane that was designed and tested entirely in silico. The same scientific approach lures us into realm of personalised medicine and data-driven healthcare. However, our clinical colleagues remind us that ‘all models are wrong’ and we argue that ‘some are useful’. Herein lies the challenge for the computational modeller. As the statistician, George Box, stated, “Remember that all models are wrong; the practical question is how wrong do they have to be to not be useful”. This talk will touch on a few real-world examples within orthopaedic research, to encourage debate and discussion on how ‘personal’ our personalised models really need to be.