You never know if the class is actually going to happen or not. 
You show up early and ready to rock. The staff escorts you to the designated location where you're left alone to stare at the clock. As was the case for me today, you may even find yourself on lockdown in a locked gymnasium without another living soul in so much as shouting distance. There may not be a phone or any other means of communication to broadcast even the most primitive form of an S.O.S. 

That's when you may find yourself wondering about the county's fire code while plotting a seemingly impossible escape from the facility in the event of the apocalypse. Because, let's be real here for a minute, if the building is on fire and everyone is in a panic, what are the chances that anyone will actually remember that you're there? 

Then, just when you think you're ready to make your peace with the almighty and accept that some future generation will discover your mummified remains in the confines of a dusty relic from a time gone by, someone will walk by the tiny window in the door that you've been stationed at for almost an hour. You'll seek to gain their attention by frantically banging on the glass, they'll stop in their tracks, unlock the door, and tell you that the class has been cancelled due to some unforeseen circumstance or another. Only then will you finally be free to go. This may be the moment where you first begin to empathize with the imprisoned population you've volunteered to serve. 

You learn to expect abrupt interruptions.
At some point, an alarm is going to sound right in the middle of savasana. It's almost always only moments after everyone was finally able to settle down and melt away. You'll watch powerlessly as participants are startled out of their peaceful repose and you'll pull out every Yoga Nidra trick you can think of to reestablish rest. 

Then a walkie talkie will sound and a metal door will inconsiderately slam behind a staff member as they exit to respond to a call. Or, perhaps worse yet, the staff will engage in distractingly loud and inappropriate social conversations with one another throughout the entirety of the class. This is when you'll understand exactly how difficult it is for your students to find even a momentary sense of peace in such an unpredictable and disrespectful environment. 

Be prepared for adverse weather conditions.
Although your classes will likely be held indoors, you'll never know if it's going to be hotter than a suburban Bikram yoga class on a Saturday morning or colder than an igloo in the Arctic Circle... regardless of the season. This is when you might have the bright idea to start a fundraising campaign that will raise the money necessary to purchase yoga blankets or an oscillating fan. Then you'll realize exactly how much you've come to love your students when you spend your own money to purchase these creature comforts. 

Participants say the darnedest things.....
The classic exercise in sarcasm that is the rhetorical question Why don't you tell me how you really feel? could be well exercised throughout much of most practices. Participants will almost always tell you exactly how they feel about the class, the poses, your teaching, the temperature, the disgusting food they're being served, and the fact that it's causing horribly painful constipation. You'll find yourself talking about poop and planning sequences which will make it easier for students to do so. If you're anything like me, you'll probably be tempted to start bringing healthy, fiber rich snacks to share at the end of each class. 

The rewards make it all worthwhile.
Sometimes they'll let you know in simple words with a respectful "Thanks for your time" and a genuine smile on their way back to their cell block. Other times they'll clue you in on the value of the experiences you provide by recalling a portion of a previous class with a wistful expression or by cracking a well timed inside joke. 

When a teen looks up at you at the end of their practice with an expression of pure bliss on his face and proclaims, "Yo, I feel like I could levitate right now.... Like I got a natural high," you'll know the decision to facilitate yoga behind prison walls was right. 

You'll discover that these students see us, their yoga instructors, in a different light. In fact, at times, we might very well be the highlight of their day... Or maybe even their entire week. Thanks to your consistency and commitment, over time, they may begin to feel safe with you. To trust you. To open their hearts to you. To share their truth with you. This is when you'll fully comprehend the metaphorical beauty of the lotus flower bursting forth from mud.