Although originally published in relation to kayaking/canoeing this post is applicable to learning a movement or sport.
Do you sense by hitting or stroking? By pulling the blade mindlessly through the water or slowly and therefore sensing the resistance of the water against the blade? The latter will educate you to the angle of your blade.
This is applicable not just to paddling but to all sensing.
Further reading: Weber Fechner http://en.wikipedia.org/wiki/Weber–Fechner_law