Mendeley Desktop is a nice academic research resource management tool. However I messed its configuration up, and got to reset it. But there is no such a directory as .mendeley as I expect in my home directory, so I got to find it like this:
for f in `ls -a1F | grep -E '^\.[A-Za-z]+/$'`; \ do find $f -print | grep -E '[Mm]endeley'; done
Then simply delete everything I got, and bring Mendeley back happily ;)

