This loss was possible only in Japan because of its isolation; there were no other neighbors threatening Japan. When firearms arrived in Europe, there were European princes who similarly banned firearms, and there were European princes who banned printing, but you can guess what happened. When a prince in the middle of Europe banned firearms, within a short time the prince next door who did not ban firearms either walked in and conquered, or else the prince who banned firearms quickly realized his or her mistake and reacquired firearms from next door. The banning of the guns could work only in isolated Japan, where there were no neighbors as a threat, and where there were no neighbors from whom to reacquire the technology.
Save money on food. I recently joined $5 Meal Plan in order to help me eat at home more and cut my food spending. It’s only $5 a month and you get meal plans sent straight to you along with the exact shopping list you need in order to create the meals. Each meal costs around $2 per person or less. This allows you to save time because you won’t have to meal plan anymore, and it will save you money as well!
Avoid purchases that are likely to depreciate rapidly. Spending $50,000 on a car is sometimes considered a waste because it's likely that it won't be worth half that much in five years, regardless of how much work you put into it. As soon as you drive a new car off the lot, it depreciates about 20%-25% in value and continues to do so each year you own it.  That makes buying a car a very important financial decision.