The principles of weight and balance should have been understood by all pilots during their initial training. It is clear that, afterwards, some forget, don't bother or are caught in 'traps' There have been several fatal accidents to general aviation aircraft in which overloading, or out-of-limits centre of gravity (cg), were contributory factors.
An overloaded aircraft may fail to become airborne, while out-of-limits centre of gravity seriously affects the stability and controllability. Pilots must appreciate the effects of weight and balance on the performance and handling of aircraft, particularly in combination with performance reducing factors, such as long or wet grass, a 'tired' engine(s), severe or un-coordinated manoeuvres, turbulence, high ambient temperatures and emergency situations.