Because paddling 5km on flat water is "Fun" for some of us mere mortals. Exercise, as you proberly well know, produce happy endorphins called seratonin's this allows mothers all over the world the ability to cope with cranky children day in and day out, without resorting to vodka, and winni blues

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Some of us, lack the knowledge and experiance of you ocean going folk, (even though we are trying really hard to learn, even with the jeers, and smart ass comments from stranger's[}:)] standing on the beach's edge, you just have to get back on the board when you fall, or never learn) so therfore "I" must get MY "fun" anywhere "I" can...and i do have fun on the flat water

and i am "learning" too have fun in the waves/ocean too