An Ngram of the term shows its birth as a "stock phrase" only dates back to the 1960s, but the words are found in print a century earlier and the first examples of the phrase being used to mean motivating, inspiring, or enabling forces or factors go back to the 1930s. I'll give you one example of each.
I found creative juices in print back to this 1846 translation (p. 182, scroll down) of Kalevala, a Finnish epic poem that recounts a mythical story of the cursed birth of steel:
I don't think this reference is incidental. The same section of this poem, with the same translation, was reprinted several times in the writings of Lafcadio Hearn at the turn of the century and as late as 1922. While not the figurative use of the phrase we have today, I think there's a good chance its occurrence in his writings led to its familiarity and adaptation in the 1930s.
The first use of it I could find in print with its modern connotation was from this 1936 article in The Delineator:
[...] and played and replayed and recorded and wrote down their early songs.
Their creative juices dried up. Only a
few of the original players stuck by
their guns, among them notably the men
mentioned in this article. They
continued, in honky-tonks, dives and
dance halls, to play as they felt and
feel as they played.
I wasn't able to get a more complete quote because of the limitations of Google's Snippet view, but it's clear the article is referring to the figurative creative juices of musicians.
One later 1930s reference of note is found in the intro to the 1939 screenplay of Margaret Mitchell's Gone with the Wind.
Looking in COCA, how come is very common in American English. It's used to mean why, in questions, and occasionally in statements:
How come the reporters aren't asking that?
And that's how come this song "This Land Is Your Land" became known throughout America.
If we break down the places it appears, a pattern emerges: how come is almost never used where formal writing is demanded, as in academic writing, but is frequently used where informality is okay, as in fiction dialogue and speech:
TOTAL SPOKEN FICTION MAGAZINE NEWSPAPER ACADEMIC
HOW COME 2689 882 1318 283 164 42
In American English, at least, how come? is informal, but probably not considered slang.
Best Answer
Basic, is exactly that, basic. For example if you say a girl is a "basic chick" she's very ordinary, unoriginal, nothing special about her. The origin probably came from the real meaning of basic, but rappers started applying it to people. In this song by Kreayshawn, she talks about expensive handbags, and says she doesn't want them because it's basic. The reason it's basic is because just about any female with the money to buy those bags are walking around with them. http://www.youtube.com/watch?v=6WJFjXtHcy4 *mild language in the video