I was step on 2 times

On the way to school, I was stepped on 2 times. While I was walking out of SEIBU line, my right shoe was step on. After I transfered to CHUO line toward KICHIJOJI to change train to MEIDAIMAE. Then, I went down stairs and sudently was step on again.Why? It is because I walk slowly or my careless.(~;;~)