The idiom "pay as you go" means that someone is making a payment for something only when they receive or use the product or service being purchased. This payment may be made in cash, credit card, or on an account basis, depending on the agreement between the buyer and the seller.

The idiom "deja vu" means a feeling of familiarity with something that is experienced for the first time or something that has already been experienced, but seems to be happening again as if for the first time.

The idiom "cave in" means to give in or yield to pressure, especially when the individual or group is reluctant to do so. It can also mean to accept something without question or resistance.

The idiom "back to basics" means going back to the original or basic principles of something, usually in order to understand it more fully or solve a problem. It can also mean starting over or beginning again from the beginning.

The idiom "batten down the hatches" means to prepare for a difficult or dangerous situation by taking necessary precautions and being ready for whatever may happen. It is often used when one is about to face an uncertain event, such as a storm or a crisis.