I have a pair of very distinctive shoes. They are a pair of old Frye boots, and I wear them everywhere - so often that once a friend of mine could tell that I was at another friend's house because my boots were in the hallway. They don't make them anymore, but these boots are some of the most comfortable - I wear them everywhere with everything - heavy leather boots that remind one a little of hiking boots, a little of paddock boots. I wear them with dresses and jeans and skirts.
But here's a secret: they aren't mine. They technically belong to my mother, who has had them since before I was born. When I was quite young she wore them on hiking trips - I don't know how long she has had them but I imagine they've been all over the world with her - to Kenya and to Thailand and to New Zealand (I know they've been all across Europe with me, at least).
These are boots that are at least twenty years old - probably more like thirty or forty, if we're being honest. I wear them almost every day, and they are the shoes that are in the best shape of any of my footwear.
I'm serious - trainers disintegrate after a while, the heels on my cowboy boots have been worn down, the linings of wellies rub away, and high heels are prone to all sorts of accidents. But these boots persist - they are older than I am, and I could imagine a daughter of mine one day wearing them and quite possibly attempting to sneak them away to university with her.
I have no idea how much those boots cost at the time my mother bought them - £100? Less? More? Anyways, however much they cost, I can almost guarantee that they were worth it and more. If you look in your closet, how many items can you find that you can wear for twenty years and more - shoes that won't break down, that won't go out of style? That's what an investment is - a pair of shoes that your kids will want to steal one day, that are comfortable enough to climb a mountain or walk around Paris in, a pair of shoes that your friends recognize.
I know I don't do this - I'm a university student and thusly don't really have that much money - but I think it's a good idea to "invest" in most everything you do. Buy the boots that stand up to the test of time, or hardcover books that you'll love forever, or the overcoat that your granddaughter will wear proudly throughout her life. Invest.