Some facts about the purple and red lines:
On the 5th stop, about 2 1/2 miles from Union Station, Purple diverges and it continues for another two stops another mile.
Red continues for another 8 stops passes under the hills and travels about 13 miles in total.
At least I thought it was the red line.
The problem was that the purple was a mere spur of the red in the summer of 2007 and both lines share a platform beneath Union Station.
Every second departure was red; every other purple.
But this was not clearly labeled, nor was it explained at all.
The LED display at the ends of the incoming trains (and they were all incoming, as this was Union Station,) told whether they were red or purple but purple (at least at that time) wasn't much, and most people there were taking the long fast journey from downtown L.A. to North Hollywood.
I got on the wrong one.
A few stops later I heard I was supposed to disembark in order to go to North Hollywood, but I didn't believe it in time.
Then I had to go back a stop, then go down one level to catch the return trip to Union Station.
At union station, I arrived just in time to catch the next departure of the purple line. But I didn't know it was the purple line.
I wasn't the only one. There seemed to be a kind of a swirling pool of people caught taking the purple line, returned from their error just in time to take the purple line people who didn't know about the alternating departures. People stuck in a loop just like I was.
It was a little scary.
I wasn't the only one who thought so. A fat black gentleman gave me a religious tract, and used the phrase "no atheists in foxholes."
It was also funny. A group of young adults in the back of the car laughed at the absurdity.
None of us knew the explanation. We got off when we learned we were on the wrong car, and we returned to the station, on the same line, and got on (what we thought was) the right train.
The tracks diverge, of course, imperceptibly to those who don't know it's happening. One of them goes to North Hollywood, and the other one doesn't.
If one were to board the purple line by mistake, de-board when notified a few stops later, go down a level, and then go back to Union Station just in time for the next purple-line departure, one could get stuck in a loop. This loop would repeat until one either stepped onto the red-line departure by the fortune of good timing, or discovered the pattern.