poetandknowit9 Sep 2002

Not necessiarily.

from tinywords.com
Haiku are extremely short poems written in 17 syllables or fewer, often (but not necessarily) arranged in three lines of 5, 7, and 5 syllables each. Haiku make use of concrete imagery or sensations, not abstractions or metaphors, and are often (though not always) concerned with the natural world.
In our view, haiku should point to an actual, lived experience and, in so doing, evoke deep feelings in the reader. As haiku poet and author William Higginson writes, "The central act of haiku is letting an object or event touch us, and then sharing it with another."