You don't need to make multiple accounts though? You go to lemmy.world, or wherever your account is and find your communities, anywhere in the fediverse from there.

To expand on the above analogy, if you are on your laptop, and your buddy is on his laptop hooked to the same network and you need a file off his computer you don't go to that computer to create an account and get the file, you just access it through the network you are both attached to. You can make comments and post all through the network.