Why is my Windows path limit actually at 243 instead of 260?

I'm using Windows 11 Pro and I've noticed that I'm limited to about 243 characters when creating a file path, even though I know the overall limit is 260 characters. I'm not looking to change this limit; I'm just curious about why I can't use that full 260. For context, the folder location where I'm creating a text file is 'D:FilesMISCABCD' which is 15 characters, and the file name I'm trying to use is a whopping 228 characters. So, even though the total doesn't exceed 243 characters, I hit a wall and can't add any more to the file name. What gives?