As a counterculture, it appeared after the French Revolution. After losing their patronage from the wealthy, many artists started a nomadic lifestyle. They hadn't got too much money so they wore used clothing and lived inexpensively. In the eye of the world, they were poor, unfashionable craftsmen, but in reality, they just had their own style of living life.
They wore colorful fabrics, strange hats, their hair was long and flowing, so nothing like the usual 19th century looks. This new folk resembled the wandering gypsies, who - according to the people of this era - originated in Bohemia, hence the expression.
A style of freedom and it's about you. If someone visits your home, they will identify the colorful curtains, tapestries with you, so forget about rules. Chose patterns you like and don't worry about the rug, it will match the other 5 in the room and the pattern of the wall. Express yourself!