From a 1995 Dartmouth College commencement address by Joseph Brodsky:
When hit by boredom, let yourself be crushed by it; submerge, hit bottom. In general, with things unpleasant, the rule is: The sooner you hit bottom, the faster you surface. The idea here is to exact a full look at the worst. The reason boredom deserves such scrutiny is that it represents pure, undiluted time in all its repetitive, redundant, monotonous splendor.
Boredom is your window on the properties of time that one tends to ignore to the likely peril of one's mental equilibrium. It is your window on time's infinity. Once this window opens, don't try to shut it; on the contrary, throw it wide open.
Jonah Lehrer adds his own thoughts.
(photo by Noah Kalina; the original post had the date at 2005.)