Igor Karkaroff's first day of his first year at the world-famous Durmstrang Institute had, largely thanks to his brothers, consisted of three major components. These were 1) getting lost, 2) getting hexed, and 3) getting his head dunked in two toilets per floor.
It was no good trying to fight them. He knew some jinxes, but there wasn't much he could do; Yuri and Ivan were sixth and seventh years, respectively, and could block anything he cast with their eyes closed. Thus, he resorted to simpler, more effective tactics.
That year, Igor got very, very good at not being found.