correct me if i am wrong but when ever someone says 'the data has noise'
the noise is almost always data that doesn't fit the person's pre-determined opinion from what i have seen.
No. Noise has particular characteristics that are independent of the model. Noise is random. There is no reasonable model that could account for the small, short-term fluctuations in the data that we call noise. However, a bad model simply doesn't fit the data very well. An example is the HL technique in the very early part of the oil production history. A straight line doesn't fit that part of the curve, and it's not because of noise.