Neighbor gives me his old ticket

Hello people, when I went to the car last night, the big shock came over me – help me a parking ticket! And that although I park there for 1 1/2 years there. Well I thought, so I looked at the parking ticket. My license plate was registered and also the street name. But now the hammer: my “parking offense” should cost 100 euros! Puuh I thought, with such amounts does not come right away the towman?!? I would like to note that there is neither stop- nor parkverbo The street is a bit tighter when I park there. So 4 instead of 7 meters. Then I got stutzig, the transfer carrier was missing and besides, the note also looked not quite “fresh”. With me came the thought “Hmm, feels a neighbor disturbed by me or someone just allowed to joke?”. Then I noticed the file number! “Hey, you can find the original recipient of the ticket easily!” then I thought to myself. The ticket is Undoubtedly real, so with seal and (forged?) signature from the Stuttgart Administrative Office. My questions to you: Has this happened to you before? What should I do? Is this assumption of office or forgery of documents? Thank you Avro