Every country has customs that shock and confuse foreigners. Polish people going about their daily business or celebrating special occasions often do things that will make your jaw drop, but are considered perfectly normal here.
A good piece of advice: beware of Easter Monday in Poland! Although this advice might seem strange, you really should take it to heart, cause otherwise… you’ll get soaked! The tradition of Śmigus-Dyngus is still going strong in Poland.