It seems to me that I have the proper permissions, so why can't I create directories in my $HOME directory?

dotancohen@neptune:~$ whoami

dotancohen

dotancohen@neptune:~$ pwd

/home/dotancohen

dotancohen@neptune:~$ ls -l .. | grep dotancohen

drwxr-xr-x 16 shelly shelly  4096 Jul  2 15:02 dotancohen

dotancohen@neptune:~$ mkdir test

mkdir: cannot create directory `test': Permission denied

dotancohen@neptune:~$