If you have forgotten about the different types of digital circuits, read this again: click here
A one-bit memory is a device that is capable of remembering 1 bit value. So you can store a 0 or a 1 value in this device, and recall the value at a later time.
A one-bit memory would be similar to a cheap calculator's Min key:
The ability to indicate precisely when the value stored in a memory element will be updated is very important because a memory element that "updates itself at the wrong moment" is a "forgetful" memory and is not very useful...
A memory device will need to support 2 capabilities: