For some people, this kind of body piercing would be totally extreme, but for local Thais, this is completely normal. They ignore the pain because this ritual is a rite of passage to adulthood. This is an annual ritual performed in public to announce to the whole world that they have become adults.
It may look bizarre for most societies in the world, but this kind of ritual is not unique to Thailand. There are other societies that have similar traditions. Its a tradition that has been practiced for several hundreds of years.
So the next time you get drunk and go out to get some weird body part pierced and think you are extreme, just remember there’s some guy in Thailand with a fire extinguisher coming out of his mouth. And you wonder why there are so many urban legends about whether Asian guys are any good in bed?