As WP points out, the nuances of false negative and false positive categories can take a while to get your head around.
Add to that the fact that the principles of epidemiology and disease control can also be nuanced and poorly understood by the general population and then stir in a healthy dose of fake news/conspiracy theory and you can appreciate that this whole sh!t-show is almost impossible to navigate through. Especially for a politician who is unlikely to be trained in any of the above and also subjected to all the other distractions such as the economy, keeping voters happy etc etc.

The main news channels like to give nice, easily digestible packages to the great unwashed but the daily stats they show are pretty meaningless. Would be much better to give daily capacity figures for NHS regions. If you knew that your local hospital was full (as in Stoke on Trent) then you might think twice about doing anything risky or ignoring covid advice.