In economics, nominal rigidity, also referred to as price stickiness or wage stickiness, describes a situation in which a nominal price is slow to adjust or resistant to change.

There is a strong incentive to raise prices when the cost of inputs goes up (because otherwise you operate at a loss). But a weak incentive to lower prices when the cost of inputs goes down (because gasoline is an inelastic good).

If it makes you feel any better, wages are the ur-example of nominal rigidity for a reason. Delivering a pay cut to employees is practically impossible. People hate that shit and will immediately start sabotaging business productivity in response, then leave at the first lukewarm opportunity, resulting in a net-negative long term return for the employer.

The optimal response to price stickiness is to jettison the source of the cost. In the case of labor, this means layoffs (people get angry at a wage cut but feel comparatively relieves when they end up with more work at the same pay scale because their coworkers got fired). In the case of vehicles, this typically means transitioning to EVs or adopting public transit.

Finally, a benefit of being way below the poverty line in my late teens/early 20s. Couldn't afford to drive so petrol prices don't matter to me!

At least it fall. When is the last time you see a restaurant decrease the price after they increase it when in some random crisis period?

Prices never fall as quickly as that