Simple analogy: designing on paper, overtime the table the paper is placed goes form polished granite flat, to being concrete, to being wood to being breeze block etc and at the same time your sharp pencil, which you can angle for thickness of line, becomes a pen that has one thickness line, that then becomes a pen with undefined thickness of line that widens over time, and then you notice on top of all that the paper has become much thinner and that you aren't actually holding the pen anymore.
Wake up.