I have got to say I totally agree with Kleiber, as always :)
You have a lifetime of fun ahead of you MiniN. Do you know anything of Jack's history, or is his age a guess?
He sounds wonderful; our Collie is called Jack, he's 3 now! And I am still waiting for him to stop being a puppy...
Jack's girlfriend (!) got him a treat ball for Christmas-available at places like Pets at Home, you fill them with treats, then close the hole so your dog has to work out how to open it and get hold of the goodies! That keeps Jack occupied for a bit. He has also been given a treat pyramid, a bit like a Weeble (it wobbles but doesn't fall down!) with a hole in that, again, you put treats in, and your dog works out how to paw it around 'til they all fall out!
Anything that occupies them and makes them think is great, there's a range of toys in that line, so stock up! You will need all yuo can get! Many woofs from me and Jack to you and Jack!x