$x is an undefined variable and must have got coerced to false somehow...
$x === NULL
false === (bool) NULL

x doesn't have a $ so must not be a variable. Maybe it's a nonempty string (not equal to '0')?
So should be coerced to true... obviously.

hang your head in shame
revealing your secrets now...

01234567
8

array(6) {
  ["_GET"]=>
  array(0) {
  }
  ["_POST"]=>
  array(0) {
  }
  ["_FILES"]=>
  array(0) {
  }
  ["GLOBALS"]=>
  *RECURSION*
  ["did_good_job"]=>
  bool(true)
  ["reveal_secrets"]=>
  bool(false)
}
array(4) {
  ["_GET"]=>
  array(0) {
  }
  ["_POST"]=>
  array(0) {
  }
  ["_FILES"]=>
  array(0) {
  }
  ["GLOBALS"]=>
  *RECURSION*
}
array(5) {
  ["_GET"]=>
  array(0) {
  }
  ["_POST"]=>
  array(0) {
  }
  ["_FILES"]=>
  array(0) {
  }
  ["GLOBALS"]=>
  *RECURSION*
  ["x"]=>
  int(0)
}
array(6) {
  ["_GET"]=>
  array(0) {
  }
  ["_POST"]=>
  array(0) {
  }
  ["_FILES"]=>
  array(0) {
  }
  ["GLOBALS"]=>
  *RECURSION*
  ["x"]=>
  int(0)
  ["y"]=>
  int(1)
}

$y === 1

112358
223469

val1, val2, val3, 
k1 => val1, k2 => val2, k3 => val3, 

ID generated: 172
ID generated: 149
ID generated: 145
ID generated: 170
ID generated: 162
ID generated: 140
ID generated: 146
ID generated: 106

IDs: Array
(
    [0] => 172
    [1] => 149
    [2] => 145
    [3] => 170
    [4] => 162
    [5] => 140
    [6] => 146
    [7] => 106
)
$ID === 106