ARGH! There's no such thing [as writer's block]. Seriously: THERE. IS. NO. SUCH. THING. You know what there is? There's a bunch of problems, creative and otherwise, that can stop you writing. They are not block. They are important skills.
Some degree of novelty must be one of the materials in almost every instrument which works upon the mind; and curiosity blends itself, more or less, with all our pleasures.