treading on tiles

ok i just got back from the shops on my way there and on my way home i walked this specific pathway along my block coz it was raining... well i just happen to look down at my feet and i noticed something. every step i took the lines the partitions between the tiles made kinda.... flickered. i dont know how else to decribe this. the distance this 'flickering' happened covered abt a metre radius around me. well not the first of this sort of thing happened i saw BMWs get warped doors and even tiny waves created on floors as i walk as if i stepped on water only its bone dry. *shruggs*