Hello.
If it is remapped it should feel like she wants to rear up and wheel spin in 1st and 2nd gear with ease, It should also give nice turbo kick which will push you back in your seat. plus if your car has traction control the light will be flashing all the time when driving hard. In other words a remap should make you smile,
Standard the power will feel the same across the whole rev band with no turbo kick, In other words the car wil feel bland.
You could plug VAGCOM in and data log the Manifold Absolute pressure channel. With the results you can compare tell if the car is running more boost than standard and it will comfirm the ecu has a remap on it.
What year is your Golf? If it is pre 2000 with the 200ab or 200bb ecu chip, then you can tell by looking at the chip inside to ecu to see if it has been remap, If it has the 400bb chip then there is no way of telling as the car can be remapped by OBD2 and Debugger remapping direct to the loom conection methods.