Why so important?
Take care of your knife and it will take care of you and your meal.
Call me Captain Obvious, but having a sharp knife will change your entire cooking experience. I never went to culinary school, and so I have definitely been guilty of having blunt crappy knives at my disposal. The day I realized what a difference a sharp knife made changed everything. It allows you to hone your knife skills, allowing for more precise and fine work. It is also HUGELY important in terms of safety (case in point: slicing though tomato skin with ease rather than having your knife push against the tension and jump onto your innocent thumb). And having a sharp knife can actually even extend to ergonomic health, avoiding exacerbating carpal tunnel, tendonitis and so forth.t.