Are You a Skinny Guy? Build Muscle Mass For Your Body Type

If you are that skinny guy, building muscle mass can seem like an impossible task as you puff and sweat and lift weights and end up exhausted with almost nothing to show for it. So why is it that those with a skinny body type seem to struggle to pack on the pounds of lean muscle they want when guys with bigger frames seem to do hardly ANY work at all, eat crap all day and still sport an impressive set of muscles at the end?