Eleven years ago I printed out a couple hundred pages of Perl reference documentation and brought it with me on an extended Christmas vacation to Iceland. I pored through it and taught myself Perl, without writing a line of code until I got back home.
To this day, Perl is still my go-to language for getting things done quickly.
I mean, what’s not to love? Coding in a language that looks like line noise just appeals to me:
$g =~ s/^\s+|\s+$//g;
$g = join ' ', map { ucfirst lc } split / /, $g;
(For those that aren’t Perl-savvy, the first line is a trim() function, while the second title-capitalizes a line.)
What about you? What’s your fallback language?