Shouldn’t I skip lower grit whetstones, and just get a 20K grit whetstone?
One thing everyone needs to understand about polishing stones - they are designed to polish. If you are not able to achieve a properly sharpened edge with your sharpening whetstones, it makes no sense to move to a polishing whetstone. All you will achieve by moving up the grit ladder so quickly is you’ll have a nicely polished dull knife. So, the answer is NO, you cannot skip your basic sharpening grits, and jump right to the finest polishing grits.