Most of you probably do more fishing in one month than I have my whole life. I'm wanting to do more of it, but I don't want to waste a lot of time and money. Casting is fun, but I'd like to actually catch fish I have some basic questions. Like, why do I need a leader for spinning and baitcasting? I understand why you would need one in flyfishing, but why would you need one if you are useing mono or flourocarbon line?