When you are in a hurry to open the stubborn jar, it does not listen to you much. It becomes harder and harder to open. The more the food inside the jar is tasty, the harder the jar does.
Stop open your stubborn jar until you sprain your wrist, watch this video of 6 easy hacks for hard-to-open things. You may meet these in your daily life!
Fine, stubborn jars! You no longer stubborn as you used to be, I surely believe these tips are going to get rid of you.