So did I, amongst several other relevant things.
The GDR border guards were /very/ touchy, and people had to be very careful not to irritate them. Things like keeping western glossy magazines out of site, not bringing East German currency out.
In East Berlin, I went in the best department store, on Alexander Platz - because they forced visitors to spend some money in East Germany. The *only* thing I found to buy were a few postcards.
I know someone whose job was to see how well the BBC was being received. He was frequently harassed.
I know someone that divorced (so his wife could come back to the UK), crawled under the wall, and was remarried.
Summary: you must have been blind.