Is that how plumbing is done? I've been doing it wrong all these years!
That'll be why my plumber has so many leaks - I'll tell him PTFE is the secret trick, failing that a bit of electrical tape should do it.
PTFE on the olive does work actually lol! I wouldn't usually do it off the bat, but if a compression fitting leaks, and they do from time to time, wrapping the olive stops it. 😉