Some things about Scotland don't belong to any particular place. They're woven through the whole country — traditions, foods, animals and symbols that tend to come up in conversation with visitors because they're genuinely curious or genuinely confusing or, in some cases, both.
Whisky is the obvious one. Scotland produces a lot of it and it varies enormously — the peaty, maritime style of Islay malts is completely different from the fruity, sherried character of Speyside, which is different again from the lighter Highland styles. There are over 140 working distilleries in Scotland currently, and the craft has become a significant part of the country's cultural identity as well as its economy. The basics are worth understanding before you visit a distillery: single malt means made from malted barley at a single distillery; blended Scotch is a mix of malt and grain whiskies from multiple sources. Age statements, peat levels, cask types — it gets complicated quickly, but the distilleries are generally good at explaining it.
Haggis is minced sheep offal with oatmeal, suet, onion and spices, traditionally cooked in a stomach. It sounds worse than it is. Eaten properly at a Burns Supper with neeps (swede) and tatties (potato) it's hearty and well-spiced. The version you'll encounter most often as a tourist has usually been adapted for squeamishness but retains the general character. Cullen Skink, mentioned in the Moray section, is smoked haddock soup and less divisive; Arbroath Smokies are hot-smoked haddock with protected geographical status. Scotland's food has improved significantly in the last twenty years and the best of it is rooted in good local ingredients.
The Highland cow — shaggy, long-horned, apparently docile — has become an icon of Scotland in a way the officially designated national animal, the unicorn, never could. Red deer are the largest land mammal in Britain and are managed on Highland estates in significant numbers; the question of how many is appropriate is a live debate. The sheep-to-people ratio in Scotland is about five to one, which explains a lot about the landscape.
Tartan and the clan system are largely an early 19th century formalisation — much of what's sold as ancient tradition was systematised for George IV's visit to Edinburgh in 1822, managed by Walter Scott. That doesn't make it meaningless, just younger than advertised. The Lion Rampant (yellow flag, red lion) is technically the royal standard and not supposed to be used by civilians, though it widely is. The Saltire — white diagonal cross on blue — is the national flag and one of the oldest in the world. Bagpipes are capable of being genuinely stirring in the right context and genuinely trying in the wrong one.