What are the motivating forces for Pip and Joe in chapters 14 and 15?

In Chapter 14 of Great Expectations Pip is pretty much marking time. He has just started his apprenticeship at Joe's forge and isn't too happy about it. Spending all of that time at Satis House in the company of Miss Havisham and Estella gave him a tantalizing glimpse into a world far away from the humble life of a blacksmith's assistant. It's fair to say that Pip's experiences at Satis House formed an indelible impression on him, briefly holding out the prospect of a better, more socially elevated existence. Though disappointed by his lowly station in life, Pip doesn't reveal his true feelings to Joe as he wouldn't want to upset his kindly old friend. For his part, Joe is pleased to have young Pip around, and is more than happy to teach him everything he knows about being a blacksmith.
In Chapter 15, Pip tries to persuade Joe that he needs to pay Miss Havisham a visit. Joe advises him not to go, but as Pip is growing into manhood, he feels that he is entitled to do as he pleases. Life at the forge is becoming increasingly unpleasant, not least because of the cruel behavior of the hateful Dorge Orlick, Joe's forge worker. So it's not surprising that Pip wants to return to Satis House, the scene of a much happier, more carefree time.
But Joe wants Pip to move on with his life; he doesn't see that there is much to be gained by Pip's taking a trip down memory lane. He's keen for Pip to learn a trade and to make his way in the world as a blacksmith. Joe only wants what is best for Pip, but as a simple common working man, he lacks the imagination to understand Pip's motives in wanting to see Miss Havisham once more.