If you lack a definite plan or purpose and flit from one thing to another, your actions are desultory. Some people call such desultory wanderings spontaneous. Others call it "being lost."
The adjective desultory comes from the word desultor, which was a circus rider who would leap from the back of one galloping horse onto another. From this literal sense of jumping from one thing to another, we get the modern meaning of desultory as jumping between things without a logical purpose.