"Not yet"
The knowledge isn't in your head right now, but it can be. Are you willing to risk trying?
This one is going to be a bit more personal, so bear with me.
When someone asks me if I can do something that I never done before in my life, my favorite default answer to give has always been "not yet".
Let's be real: most of us, designers (and product people, and engineers, and probably everyone) get asked to do stuff they've never done before. Not occasionally — constantly. New constraints, weird edge cases, tools that didn't exist six months ago.
We default to either overconfidence ("yeah, sure!"), or defensiveness ("that's not really my area"). I never liked either of those options.
I learned "not yet" from my Dad. He's an electronics engineer who worked on some of the most complicated things that I have ever encountered in my life — from scanning electron microscopes to giant hockey stadium displays.
The real constraint for him was the context: People's Republic of Poland, closed markets, nothing available on demand, dependence on USSR for a lot things. You couldn't just order a specific microchip from Texas Instruments that would work perfectly for your problem because (a) it was probably too expensive, and (b) it was imperialist and here we don't import imperialist products. You made it work with what you had.
One of my most nostalgic memories of childhood is falling asleep on the pull-out couch surrounded by the smell of rosin, while my dad soldered through the night on some kind of next thing that would be great if it existed. Not just because he was a hobbyist — I mean, yeah, he probably is, he still loves building things even in retirement and has a separate room in the house now for "the lab". He did it because there wasn't another option. When you don't have access to everything in the world (the fact of modern life that I'm immensely grateful for), you learn how to make things and you make whatever you need.
That's the thing about "not yet." It's not optimism. It's not pretending the gap doesn't exist. It's just stating a fact: the knowledge isn't in your head right now, but it can be. The alternative — "no, I can't" — is a permanent state.
"Not yet" has an expiration date.
Dad got me into computers. Not by going to the store and getting one (couldn't do that, remember?), but by figuring out how to get one. Talking to people and finding the way was how I had a ZX Spectrum as a kid. The path I'm on — electronics to computers to CS to HCI to design — wasn't a master plan. It was just following the next "not yet" until it became "okay, now I can."
Vibe coding, AI interfaces, localization pipelines, graph databases, helping humans connect with each other — none of this stuff comes with a manual. You either treat the unknown as a stop sign or as a temporary condition. "Not yet" keeps the door open without pretending the room is already furnished.
It only works if both you and the person who asked are willing to sit in the discomfort of not knowing while you figure it out. (And burn through a few prototypes that smell faintly of regret.), but it beats the alternative: staying inside the narrow box of what you already know how to do.
The most useful skill is knowing you can learn how to do the thing. My Dad didn't build those things because he was an expert. He is a very good engineer, that's for sure. He does have an Electronics degree. But "not yet" is often the only answer to move forward.