Bielefeld does(n't) exist

In the past 2 days 3 different groups of Germans have explained that there is a saying in Germany "Bielefeld doesn't exist".
It all started when a group of motorcyclists from Stuttgart arrived into the backpackers in Kaitaia. I approached them in need of a 15mm spanner to loosen my pedals. I leave my pedals relatively loose as they inherently self tighten when you ride and it is a requirement to remove them to ship the bike. (If you get to the airport and can't undo them you have a problem). For this reason I carry a relatively lightweight 15mm cone spanner attached to the bike at all times under a drink bottle bidon cage. You can use an Allen key to remove the spanner for the pedals. I tried to loosen my pedals ready for the bus from Kaitaia to Auckland, but found that the tightening I saw happen at the Taupo bike shop was more than I could undo with my spanner.   The motorcyclists obliged with a heavier 15mm spanner and some added brute force.   Later, one of the group explained that he wasn't from Stuttgart like the rest of them, that he worked for a Stuttgart company but came from Bielefeld.  Apparently most Germans don't know of Bielefeld or if they do they know the saying that it doesn't exist. He's not used to people especially foreigners saying, that names familiar, where precisely is it, I think I've been there. He responded with between Hanover and Dortmund to which I replied I think I camped in a pine forest in the rain near there. He then expanded on his real home.  He actually comes from Oerlinghausen but refers to the larger Bielefeld, because nobody knows Oerlinghausen.  "Oerlinghausen" I repeat to him, yes I'm sure I know those names. I look on my phone but the 300 photos I carry on the phone don't feature these locations, I pull up my web photos, click on Germany and advance to the relevant page and there is a photo of the tent under the pines, but my caption reads "Helpup" as the locality.  The guy is amazed, nobody has every heard of these places and I've camped just down the road from him. Helpup he says is maybe 5km from his house.  My caption relates to the first sign I saw the next day, so I was actually closer to Oerlinghausen than 5km. He shows me his home in Berliner Strasse. I refer several times during the conversation to a supermarket I sought rain cover at prior to camping. When I look back at my scanned diary of the day I see the supermarket is named in the diary as being in Oerlinghausen, I locate the supermarket that I stopped at on the Google Maps satellite photo and it is less than 1km from this Kaitaia motor cyclists house.
The following day in Kaitaia, when recounting the story to another German guest, he tells me of the saying, "Bielefeld doesn't exist" and as he says it two girls walk into the far end of the kitchen and protest, saying "Bielefeld does exist, we come from Bielefeld"