One of the more interesting parts of plotting is getting the characters somewhere they don't want to go. In extreme cases, somewhere no-one with any sense is going to want to go. It's got to be done with care, because otherwise you end up killing suspension of disbelief (as the infamous rejection letter goes, "Suspension of disbelief does not mean hanging it by the neck until dead.")
Sometimes it's easy: your average hero will ignore the ten foot warning signs and the assorted Omens of Doom if his girlfriend is in there. On the other hand, he's not going near the Fortress of Ill Repute unless there's a bloody good reason. Said fortress being well supplied with Damsels of Negotiable Affection is usually good enough.
Absent a kidnapped sweetheart or a supply of Damsels of Negotiable Affection, you - the author - are going to have to convince your recalcitrant hero to get himself to the Fortress of Ill Repute so he can defeat the villain and the appropriate happily ever afters can happen. (Okay, if you're writing science fiction it's probably a Spaceship or Planet of Ill Repute, but you get the idea, all right? I think in weird metaphor and appalling allegory). This often turns into something of a battle of wits - and boy is it ever embarrassing when said hero outwits you.
I write in a kind of fugue state, okay? The number of times I've written something and come back later and thought "I wrote THAT?" - good, bad, and mind-boggling - isn't something I care to count because I ran out of appendages a long time ago.
Anyway. Here I am, carefully arranging all my obstacles so my hero's only viable choice is to go to the Fortress of Ill Repute, so the sneaky sod doubles back and heads home, figuring that the villain isn't as bad as all that, and besides, his home isn't in any danger. Now what? It's not exactly feasible for the villain to kidnap his girlfriend, especially since the hero so far hasn't shown interest in intimate relationships with anything, although I'm not that sure about the horse... And he's right. His home isn't in any danger. It's miles away, bad terrain, and bloody difficult to get to.
Random raiding parties doesn't cut it either. Who's going to raid in Back Of Nowheresville when they can have the riches of Fantasy Utopiana for a lot less trouble?
Well, let's see. He is a hero, therefore posessed of a certain amount of honor. He won't turn down an old friend who travels all that difficult bloody terrain, trailing raiding parties, natually, because the old friend has a Secret the villain would kill to possess... Or possibly the old friend is a Secret (See Diana Wynne Jones: Tough Guide to Fantasyland for more detail about this sort of thing). Or maybe old friend is actually old mentor's daughter and went looking for hero because her daddy said to find him if she ever needed help.
Suddenly, not only is the hero in danger, so is his home, and his family. Plus, he's got this person he's honor bound to help, and some kind of questy thing. Yay. I've got the stubborn SOB out of his comfort zone. Now I can harass and push him to where I need him to go, frustrate him into making mistakes, and generally make his life miserable unless he does things my way. Even then, it's not going to be nice, but it does get him out of the whole deal more or less intact, with a girlfriend as well.
I admit this is something of a gross oversimplification, but tactics like these work for me. A hero's greatest strength is also their biggest weakness because you, the author, can use it against them in ways they can't defend against. Although you can expect them to complain bitterly in your dreams, and demonstrate a remarkable command of language unbecoming to a hero.
How do you deal with unruly characters and get them to do what they need to do?