There are thousands of pilots with 18,000 hours plus.
I retired with over 30,000 accident free hours when I turned seventy, at that time I was still actively flying in the air show circuit in Europe.
I started my commercial flying career flying a J3 Cub spraying tobacco in southern Ontario.
Now that my flying career is spooling down I am building a Piper J3 clone which will bring my career full cycle.
In between those two time periods I have lost track of what I flew but it included a lot of different machines both fixed and rotary wing.
So 18,000 hours is really not that unusual.