Even ten minutes, and it's called growth.
Of course you could send abusive mail to your future self...
Have you seen the most recent season of Red Dwarf from late last year where Dave Lister gets upset that he's never really treated is kid right, given him good advice or steered the boy towards being a better human being... And there was something about Fathers Day muddled into it as well.
Lister then set up a whole bunch of crap to twat his kid when he was too drunk to remember what he had done the following day as he received a series of time delayed vid-mail from his dad.
(There was a time travel thingy years earlier. Lister is his own father. Sure you know that, but there are Americans spying on this conversation.)