The whole world had already been created with hills and mountains, valleys and rivers, streams and brooks when the Tisza was standing on its own before the Lord's throne.

-What can I do with you, my poor child?-, asked the Lord.
-Just trust me, Father-, said Jesus Christ, - I can arrange all this.

Having said that, Jesus took a golden plough and harnessed a donkey to it and told the Tisza to follow the donkey and the plough along the furrow. Thus he set the plough against the soil and it ploughed the bed for the river which followed it faithfully everywhere. However there was a lot of "cötkény*" scattered all around and the donkey was feeling hungry, and it is well known how fond of cötkény it is anyway, so he reached after one and then another and left the straight path pulling the plough behind him. This is why the Tisza is so unpredictable, so winding and meandering.

( *cötkény = thistle )