Investment plans that ignore, or pay only the whisper of lip service, to investor behaviours, are ultimately futile. Ultimately, the true job of a financial adviser is not to give clients a theoretically ‘optimal' solution, but to give them the best solution they could realise in practice.An investor's feelings are part of an investment's total return. In investing - and in financial decision-making generally - the right thing to do for long-term financial wellbeing is invariably an uncomfortable thing to do.A suitable investment portfolio should be judged not only by whether it could ultimately afford the investor the opportunity to do what they wanted to do when they put the plan in place but also by how the investor felt during the journey, and the costs of all those emotional deviations from the plan along the way.