This characteristic is part of what makes SPD so confusing and disorienting for everyone involved. Both the person with SPD and those around them may feel it is a (self)-discipline issue when they see that they are able to do something one day and not the next. "See, that means he CAN do it, he just WON'T -- you just need to be more firm with him," people will say. But no amount of firm discipline will create a neurological ability that just isn't there on those off days!
Don't forget to stop by Hartley's Life with 3 Boys to read 30 Stories in 30 Days, guest blogs from 30 different families about their experiences with an SPD child.