The idea of knife sharpening is extremely complex. There are all sorts of things involved such as what kind of steel the knife is made of, what the angle of bevel of the blade is, what the cutting surface is made of, why all this matters, etc.
All my knives are sharp. I think understanding honing is very important when it comes to owning and enjoying a sharp knife. The nice thing about honing is it doesn't remove steel. I hone my knife almost every time I use it, and I typically sharpen a knife way less than once a year.
The tomato test works well for me. Set the blade of the knife on a tomato. Hold the knife loosely by the handle so that the weight of the knife rests on the tomato. Pull the knife towards you gently - and do not push down. The weight of the knife should begin to slice through the tomato skin. If it doesn't, a quick and simple hone which takes only a few seconds will solve the problem like magic. The knife slices right through.
I'm always amazed by how much sharper the knife becomes with a simple hone.
If the knife doesn't slice through the tomato skin, this means the blade is really hammered, it would need to be sharpened which grinds steel off the knife.
So moving forward with your sharp knife, it's important to think about your cutting surface. I use a soft wood cutting board for my good knives, and a plastic cutting board for my cheap knives for convenience. Cutting on a marble countertop or steel surface will, of course, damage the knife blade.
Here's a simple vid visually describing what honing does and why it works.