A trillion is a gigantic number. Really, really gigantic, but most people can't truly understand the difference between a million, a billion, and a trillion because those numbers are almost unfathomable.
So instead of using money to describe numbers, I'm going to use time. I fudged some dates or numbers to use major events; forgive me.
1 (one) second ago, you started reading this sentence.
10 (ten) seconds ago, you were about halfway through my first paragraph.
100 (one hundred) seconds ago, you were reading someone else's comment (depending on how this is ranked).
1000 (one thousand) seconds ago, if you started browsing reddit, you're probably finishing around now. My source is very old, but it's the most recent that I could find.
10,000 (ten thousand) seconds ago, if you started watching The Dark Knight or The Dark Knight Rises, you'd be ending around now.
100,000 (one hundred thousand) seconds ago, you were browsing yesterday's reddit.
1,000,000 (one million) seconds ago, if you felt sick from a bad case of the flu, you'd be feeling better around now.
10,000,000 (ten million) seconds ago, if you got pregnant, you'd start showing around now.
100,000,000 (one hundred million) seconds ago, Deepwater Horizon just stopped leaking.
1,000,000,000 (one billion) seconds ago, President Reagan was one year into his first term.
10,000,000,000 (ten billion) seconds ago, the Salem Witch Trials were happening.
100,000,000,000 (one hundred billion) seconds ago, the Trojan War just ended and Helen of Troy is about to commit suicide.
1,000,000,000,000 (one trillion) seconds ago, the oldest known cave paintings were being painted.
10,000,000,000,000 (ten trillion) seconds ago, Neanderthals had just started wandering the Earth (although some estimates say they were around before then).
100,000,000,000,000 (one hundred trillion) seconds ago, Africa collided with Europe to form the Mediterranean Sea.
1,000,000,000,000,000 (one quadrillion) seconds ago, South America detached from Antarctica and the Alps started to rise.

More of these in this Reddit thread. Another classic:

The number of ways to shuffle a deck of cards is 80,658,175,170,943,878,571,660,636,856,403,766,975,289,505,440,883,277,824,000,000,000,000.

To wit, “There are more ways to shuffle a deck of cards then there are atoms in our solar system.” Or, for a more impressive party conversation trick, have someone shuffle a deck of cards and then note that the arrangement of cards they just produced has likely never been seen in the history of the universe.