If you cook at home, or work in a kitchen like me, I strongly recommend having a sharp knife! Using a sharp knife is for the most part safer than a dull knife if you know what you are doing. To cut something with a dull knife you have to use a lot of strength, and if it slips and hits your hand, or someone else, you will be surprised how well that dull knife can cut. While a sharp blade can cut you without needing strength, I can tell you from experience, I would rather have a cut from a sharp knife than a dull one, the sharp knife will make a cleaner cut and won't rip and tear your skin like a dull knife, so the sharp knife wound will heal much faster, and hurt less than the dull knife wound.
When you use a sharp knife, you shouldn't have to use much strength to cut much of anything, it should glide through vegetables, and meat. If you use a sharp knife to cut your vegetables and fruits, they tend to take much longer to spoil because you are not crushing the food. Think of a bruised apple, the bruise always spoils faster than the rest of the apple right? Well a dull knife will bruise the apple along the whole cut.
With all that being said, you shouldn't go out and buy a whetstone or take your knife to a shop to spend $20 dollars to get it sharpened (unless you are really into this and want to spend $20, or even more for a whetstone). But you should know how to take care of your knives.
The first thing I always see that breaks my heart, is people placing their knives with all their silverware or other knifes, and letting the edges bend, chip, and dull. This is not only bad for the knife but unsafe for you, and whoever needs to grab silverware, or whatever you may keep with your knives. If you really have no where else to put them, there is a simple and FREE solution to this problem.Old paper towel rolls! They are durable enough to hold your knives, they easily protect both your hands, and the knifes edge from silverware. It may not look pretty, but it gets the job done!
The second thing that can easily be fixed, is cutting things on hard surfaces. I have seen glass, and marble cutting boards, and people using plates as cutting boards. While glass and marble may look pretty, wood or plastic, is much cheaper and better for your knife. If you use ceramic plates out of convenience, then think about the long run, if it is a knife you like, it will be dull in no time, and you either have to sharpen it or get it sharpened. So just break out the wood/plastic cutting boards please!
I thought about teaching how to sharpen/hone your knife in this post, but I think taking care of your knives should come first! So I shall teach honing and sharpening later, stay tuned!