I know when a series is conditionally convergent and I understand that being conditionally convergent means that rearrangement of the terms will not always lead to the same sum, but I am unsure why exactly this is important? I have not really experienced a time where I am rearranging terms anyway (I am in Calc BC so maybe later on I will but not now). I am studying Taylor Series right now and it seems that conditionally convergent series still converge even if it is not "absolutely". I'm worried I'm missing some large concept because I do not see a big importance if something is conditional or absolute. Thanks for any explanations, I have tried to look online but everything I find seems to only explain how to determine conditional convergence and not the importance (other than explaining the rearrangement of terms part).