My lovely (and very patient) Hindi tutor Manisha just came back from a month in India. I got to see her on Sunday and she taught me a new and highly relevant vocabulary word. The feminine noun चहल-पहल (cha-hel pah-hel... that's a really rough transliteration) means "liveliness" and can be used to describe, say, the craziness of activity on your average city street in India. Or my brain at the moment, which also seems to be bursting with activity. चहल-पहल, like so many other great Hindi words, is onomatopoetic- it sounds like what it's trying to describe. You can just imagine the sound (and sight) of चहल-पहल as you say it.