Yes hun... when you fly a connecting flight back you have to go through immigration, grab your luggage, go through customs, recheck your luggage and then go back through security and to your gate. If you go through a large airport like Miami or Atlanta...it can take about an hour or more to do all of that.
AND if you purchase any liquor or liquid items that you carried on the plane you will have to put that in your luggage before rechecking.