I am aware that negative thoughts attract negative energy

After a break-in, people notice every unlatched window on the street for about a month. The windows were always there. The filter changed.

Mood works as a filter too, and a thorough one. In a bad hour a colleague's short reply is coldness, the traffic is aimed at you, and the day assembles a fairly convincing case — using real evidence, just not all of it.

Knowing the filter is on doesn't switch it off. It does let you attach a note to whatever it concludes: *this is the four p.m. reading.* You can take another one tomorrow, when the light and the blood sugar are different.