What's the penetration of design patterns in the real world? Do you use them in your day to day job - discussing how and where to apply them with your coworkers - or do they remain more of an academic concept?
Do they actually provide actual value to your job? Or are they just something that people talk about to sound smart?
Note: For the purpose of this question ignore 'simple' design patterns like Singleton. I'm talking about designing your code so you can take advantage of Model View Controller, etc.
Any large program that is well written will use design patterns, even if they aren't named or recognized as such. That's what design patterns are, designs that repeatedly and naturally occur. If you're interfacing with an ugly API, you'll likely find yourself implementing a Facade to clean it up. If you've got messaging between components that you need to decouple, you may find yourself using Observer. If you've got several interchangeable algorithms, you might end up using Strategy.
It's worth knowing the design patterns because you're more likely to recognize them and then converge on a clean solution more quickly. However, even if you don't know them at all, you'll end up creating them eventually (if you are a decent programmer).
And of course, if you are using a modern language, you'll probably be forced to use them for some things, because they're baked into the standard libraries.