Let's consider that your component was being used in a t:loop and that the current loop value was passed to your component as a @Parameter.
We know that tapestry's static structure / dynamic behaviour means that there is only 1 instance of your component (rendered multiple times). So, what would the value if the @Parameter be in the event? Hopefully this example shows you why you need to pass the @Parameter's in the event context. If it does not make sense, read it again!!
