For the record, this is not true.
All players start at the mid-way rating (somewhere around 12k - I’m not precisely sure in the new system).
This is so that new players added to the rank pool don’t distort it up or down, because a new person joining the server could easily be a dan or a beginner - we have know way of knowing.
All players also start with a very high “rank uncertainty” - IE how sure are we about their rank - not sure at all. It’s something like +/- 5k.
So initial ranks look something like 13k +/- 5k.
The higher rank uncertainty is, the quicker rank moves each game, so beginners start at the midpoint and rapidly rank down after a few games.
In the OPs case, his first couple of games were experienced players who bailed on him ( 
) causing him to win, and the rating shoot up wrongly. This has been fixed.