Came across
Gravity Is A Harsh Mistress on TvTropes.org and laughed out loud at the following section:
Named for a line in The Tick (who complains about gravity working all too well, at the time. Luckily he is Nigh Invulnerable). The author may or may not have stolen it from an earlier Garfield strip, which itself is a riff on the title of the novel The Moon is a Harsh Mistress by Robert A. Heinlein. Which is in turn a play on the sailors' saying "The sea is a harsh mistress". Which probably goes back to The Bible "The Law is a harsh master" (Romans 7, 1-6). And then Cassandra Claire plagiarized it in The Draco Trilogy.
(What makes it even funnier is that I got there from the link about The Draco Trilogy.)