To continue this logic, if “nobody” says nothing it could be construed as the start of the conversation, implying the subject came to the conclusion without prompting or context

The way I understand it, it’s a play on “Nobody asked” using Colon denoted dialogue

Nobody: [insert question]

[subject of meme]: [answer to question]

And has become increasingly esoteric through extended use

I love Bandcamp Fridays, I save up for them, always a good time