What is the single idea that naomi shihab nye is expressing in " the rider "

The idea of freedom and finding your happiness is what she is trying to convey.  She tells the character in the poem to go as he can to leave all his loneliness behind and find happiness.  Don’t let your sadness put you in one place.  If you can, leave your worries find what you are looking for.

the development of trade during the middle age increased to the change given in the agriculture, which gave money, industry and markets a bigger importance in economy. the agriculture production was more than the consumption, which meant the creation of wider markets out of the areas. besides, with the end of multiple wars, the population increased and new trade routes were created.