One of the hardest parts of working in a new domain is that it takes time to figure out what will remain useful from your past experience vs. what no longer applies vs. what will lead you astray.
This is a significant problem when you transition from a world where your purpose was to be good at your job to one where you're tasked with exploring an unsolved problem.
With enough trial and error, you'll likely be able to adapt to any scenario. However, if you are working under time constraints—like if you're working on a startup—you have the added challenge of needing to adapt within a specific timeframe.
There are a lot of compounding factors here.
First, you often may not realize the context has changed until it's too late. And even then, you may also need to check your assumptions since they may not necessarily apply to your current situation. Further, your ability to do this may be hindered by how you perceive your own identity. One's self-awareness can't be turned on like a light switch.
This is the type of problem that you address by changing how you prepare. That is, there's not much you can do in the moment. Instead, you need a preventative approach.
Simply having hobbies, creative pursuits and side projects that necessitate interacting with other people can be helpful since they catalyze the creation of new experiences you wouldn't otherwise get at your job. These experiences may give you broader perspective which may make it easier for you to adapt when you need to. Similarly, finding ways to signup for new challenges or to find or create relevant peer groups can be helpful as well. Essentially, find a way to gain a breadth of experiences.
In doing so, you're preparing yourself to more quickly shed your defaults—your instincts, assumptions, vocabulary—if not disavow them altogether once you recognize they no longer apply.
The world is constantly and quickly changing—especially now—and so an over-reliance on what has served you well in the past may hinder your ability to adapt to the present.