Hi Leigh,
Good to see you're in on this too
The first part of your regex removes the brackets and its contents but what the OP is after is for it to also removing any extra spaces left over after the removal.
So this:
" (123) The (b)big brown(wn) fox jumped (jumped) o(344)ver the lazy dog (123)"
... becomes this:
"The big brown fox jumped over the lazy dog"
Good to see you're in on this too

The first part of your regex removes the brackets and its contents but what the OP is after is for it to also removing any extra spaces left over after the removal.
So this:
" (123) The (b)big brown(wn) fox jumped (jumped) o(344)ver the lazy dog (123)"
... becomes this:
"The big brown fox jumped over the lazy dog"