Related:

• It is fruitless: to become lacrymose over precipitately departed lactate fluid.
  to attempt to indoctrinate a superannuated canine with innovative maneuvers....
• You can't teach an old dog new trick
• You cannot teach an old dog new tricks.
• Scintillate, scintillate, asteroid minikin. -- Members of an avian species of identical plumage congregate.
  -- Surveillance should precede saltation. -- Pulchritude possesses solely cutaneous profundity....
• Can you teach an old Sysop new tricks?
• People keep telling me that I am never too old to learn, and I keep wondering why they say that you can't teach an old dog new tricks.
• Dammit, I'm no supervising technician. I'm a technical supervisor.
  It's too late to teach this old dog new tricks. -- Homer Simpson Homer's Odyssey...
• An old dog slowly being forced to learn new tricks.
• If (dog_age="old") then (num_tricks=max_tricks)