There are many good reasons to take a few days to go exploring with your tent and bike in the highlands. Below I've tried to explain a few. Needless to say I've omitted the many reasons why you may wish not to, because that would just spoil the surprise.
1. Because its the law! Or at least, not against the law, at least, so long as you aren't camping in someone's back garden, and its not the stalking season, and you're not actively destroying the hills with a big spade, and you're not tickling trout (I have no idea what that last one is either, but apparently its very illegal. Dirty beggars). Obviously none of this applies to our less progressive neighbours south of the border.
2. Because you don't need a car. Trains can take you everywhere in comfort, and with a warm tin of extortionately priced Tennent's thrown in. Result!
3. Shiny things! Run out of stuff to waste your money on and annoy the girlfriend with? Then welcome to the world of lightweight camping. The best bit? They like titanium and carbon almost as much as cyclists do.
4. New pubs. The smallest, the dirtiest, the most remote and the most spectacular. You will spend time in them all, meet all sorts of folk and re-tell all your best lies/stories.
5. Staying in bothies. Like hostels only free, but with no facilities. Or lights. Plus they have mice.
6. The morning after the night before. It may have been dark, and wet, and 2AM, when you pitched your tent, but waking up to new surroundings the next morning cannot be beaten. Unless you're hungover.