I never buy into this naming weed crap. Its just some guy sitting in place packaging bags and thinking up gay names like AK-47.
Thats what i "have" now. A couple weeks ago it was OG kush. whatever the fuck that means
You must have just started using weed, did you? Maybe your dealer or grower only has one strain that you've been exposed to. While it is true that some buds close in genetics may be similar, any two plants--unless they are clones--are never the same, much like humans. When you start to learn about the genetics and how different environments bring out different traits and that the plants slowly adapt over generations making different regions unique at producing different kinds of weed.
While you are right that the name doesn't mean much for the most part, there are chemicals in the oil called terpenes which give cannabis a lot of it's different unique smells, tastes, and effects. Sometimes either the taste or smell ( and even the effects ) is reflected in the name. An example of this would be the purple strain Grape Ape. While the color doesn't mean anything, the terpenes in this plant actually give it a sweet grape smell and taste--it just so happens that the color matches the rest of the profile. You'll get familiar with this sort of stuff over time. I've smoked a strain called Lemon Skunk by DNA genetics and this strain has an abundance of the terpene limonene. This same chemical is in the leaves of the Lemon Balm plant and a lot of citrus fruits like lemon and limes, hence the strain name, and this stuff really has a strong lemon flavor. Limonene is actually the chemical that gives OG Kush that strong lemony fuel taste. While these chemicals add a nice taste/smell, it's not all they do, they actually have effects of there own. These terpenes, the main ingredient in essential oils are extracted from all sorts of plants for use in aromatherapy, limonene happens to be an anti-anxiety agent. You can buy a lot of these essential oils at local pharmacies and health food stores for use on your own from aromatherapy to flavorings in food. Myrcene is a terp in cannabis that gives sedative effects that are common with most indicas (short bushy plants, wide darker leaves) and is one of the reasons people get tired and burn out aside from the cannabinoids. Another example is pinene which can be found in the needles of coniferous trees such as pine and I believe spruce as well as cannabis. This chemical is what gives it it's pine smell and also has effects of it's own, so you see where I'm going with all of this.
Although myths or misinformation spread makes many people believe that the only effects you get from weed are from THC and it's all the same, along with THC there are other active cannabinoids as well in varying amounts in different kinds of plants. So, all of these variables are what gives different weed such varying effects. Of course cross-breeding plants can mix these traits coming up with new flavors with different effects and is the reason we have so many different tasty varieties today. Hopefully this helps to bring a little more appreciation and knowledge about different strains of weed. Good luck with your future toking (and eating). Peace out!