Ignoring the /s ... a yard is still a fair bit longer than the average stride length - it's probably about right if you're close to 2m tall though. OTOH an average male adult's hip is around 1m from the ground. Pineapples and cabbages typically weigh close to 1kg. Fist-sized rocks can vary enormously in weight - anywhere from a few 100g (pumice etc) to over 1kg (pyrite, assuming a large hand size).