Name the thing that the catchphrase is associated most closely with. Then provide more for others to guess. Try not to be too obvious (“I’ll be back”, “wide stance”) or too riculously obscure – better to provide more than one to keep things moving. You should wait for confirmation unless you are absolutely certain of what is intended.
Three to start:
I’ll show you the life of the mind!
Is it safe? (two possible answers come to mind)
The long blue tunnel to the afterlife (6 people have read this book)
(commentary is optional)