A very common maxim in the Fighter Pilot community and one that has other iterations in a bit more colorful language.
Not only will this advice keep you out of trouble as a newbie in a Fighter Squadron, but works really well in business as well. You can gain a lot of knowledge and insight from your instructors by just shutting your lip and listening, absorbing. The same is true when meeting with customers, clients or prospects.
Take the time and effort to actively listen to others you do business with or work for. Some of the best salesmen are the ones that let the customer do the most talking. They find their need or “pain”.
In your next client meeting, see how long you can actively listen before going in to your pitch. Keep your questions open ended and really get the person talking deeply engaged. Find out their interests, likes, dislikes, hobbies, and family before your start your sell. Things seem to go a lot smoother and it is way easier to build rapport.