The thoughts are free
A special variation of well known german song:
Die Gedanken sind frei,
der Lockdown beendet.
Das Grundgesetz gilt,
ganz klar, für alle Menschen.
Wir leben in Frieden,
Liebe und Freiheit.
Die Gedanken sind frei,
es bleibe dabei.
One of the best collection of sources about the topic is from Swiss Policy Research:
Update from 17th of February 2023: I do not agree with all of the conclusions from above source and take it that some of their results come from assumptions that have never been proven to be true.