Well, at least that's what my grade 5 teacher told me way back in 1980. I have to agree with her to a certain degree on that point too.
Tonight I did some watercolour pencil drawing/painting as a work colleague loaned me an Aquash Water Brush to try out. I ended up resorting to a liner brush as I just couldn't get the feel of the Aquash Water Brush.
In all honesty...I'd rather use watercolour paints than attempt the pencils again. I will leave the pencils for sketching painting designs onto canvas. I will, however, finish this drawing/painting and then ear mark it to go on a canvas with acrylic paint.