He's not wrong but he's not all right. Only you know what you are willing to invest. Making it through medical school is strenuous and will take a lot of willpower, hard work and long hours. It also doesn't end there because doctors and lawyers do crazy hours. No can know exactly what you are capable and willing to do and medical school is a possibility although an extremely challenging one. You can't just be an average doctor, to be a doctor you have to qualify. It's not like being a soso financial consultant.