Vergiss Deinen Schirm Nicht was a sidewalk chalk writing workshop initiated to get the know the residents of Andreaspark 1, a modern apartment housing block built in Schwamendingen, Switzerland in 2003. When visiting Andreaspark 1, Philip Matesic continually noticed the courtyard as a major focal point for almost all of the residents. They would pass through it on the way to the bus and parking garage, play with their children there or look down from their balconies.

During the one-day workshop, Matesic asked the residents he encountered to write one sentence of advice in sidewalk chalk, visible to their neighbours, on the asphalt of the courtyard. This was not only an exchange between Matesic and those living in Andreaspark 1, but also an opportunity for the residents to have a conversation with each another, through anonymously written sentences of advice.