It’s astounding when people think that advertising doesn’t affect them. And yet companies continue to pay billions for adverts...
I limit my exposure to marketing as much as I can.
It's called making data-driven decisions.
Step 1: Find a set of products that solve your problem based on independent reviews, e.g. what Stiftung Warentest writes.
Step 2: Use several price comparison engines, e.g. idealo, Preispiraten, Hardwareschotte to find the cheapest option for the products.
Step 3: Order there.
If you methodically follow this algorithm, you are immune to making ad-based decisions.
Human behavior is contagious, and advertisers know that. That's why actors in commercials pretend to be just another person like the viewer while lying about performing some action or behavior that the advertisers want the viewer to copy. I don't think that it's possible to suppress that behavior-imitating instinct completely. Humans are generally not very rational creatures -- not even the self-proclaimed rational ones.
Many ads are not just about some product that one might really need, like a keyboard or other equipment that is essential for a person's work. Many ads I see are about junk food, bad lifestyle choices, and trying to convince the public that bad entities are actually good entities (example: greenwashing).
Of course if you're a SV programmer earning 5-10 times the average wage, you don't care about this and buy overpriced shit every day, but many people follow this to the letter.