IIUC, you're not missing anything though your interpretation is off from mine*. He wasn't saying it'd be hard, he was saying it should be done.
* my understanding was simply that the regex would (A) recognize `[a-z][A-Z]` and inject optional _'s and -'s between... and (B) notice mid-word hyphens or underscores and switch them to search for both.
* my understanding was simply that the regex would (A) recognize `[a-z][A-Z]` and inject optional _'s and -'s between... and (B) notice mid-word hyphens or underscores and switch them to search for both.