It doesn't have to make sense - it's a dream.
When I start my car, I have to press the brake pedal and push the start button. But this time, when I pressed the brake pedal, it went down freely, no resistance. So I had no brakes!
I knew that this was because I'd was without brake fluid. Fortunately, I carry some in my boot, so I poured the contents of the bottle into the brake fluid container, but there wasn't enough. I needed more. So I got my bike out of the back of the car, and pedalled to the nearest garage, where I bought a bottle of brake fluid. I biked back to the car, and used that to fill up the brake fluid reservoir.
And then I woke up.
Actually, I don't carry a bottle of brake fluid, but I do carry a spare can of diesel, a jump-starter battery and an good kit of tools.