Thoughts on carrying extra magazines

I'm not trying to be sarcastic or combative on the topic. I'm simply asking the question and hoping for intelligent answers and opinions as to why and how many others think is the right way to go.For me, my current need for CCW is to de-ass the situation, such as attempted mugging. Are we thinking we need multiple mags to drive off a mugger? Or are others carrying extra magazines because you anticipate getting in a prolonged firefight?Do I need to carry 30-45 rounds off ammo all the time? Less? More? As much as I can carry? I'm lost on this topic as to what might be reasonable. If I'm carrying for self defense, is there a point where it has become for offense purposes? How many is too many? Is there even a too many, lol?Again, not trying to say anyone is wrong on this. I encourage others to do what's best and most comfortable for them. I'm not opposed to carrying extra but I'm hoping to hear other's thoughts on the subject matter and their reasonings.Thanks! via /r/CCW http://ift.tt/2DDsOu4