Pain water is very similar to tears, but not really through sorrow. You're not crying because you're upset, but because you're either talking about something you are passionate (and tears flow because it's about something that's been denied from you for so long) or a bad memory that causes trauma in years to follow. This can also be attributed to
physical
pain, where you may be hurt to the point of the body producing
water that pours from the eyes.
It's important to know that you're not sad, but rather dealing with
pain that is either psychological, emotional, or physical. Most men may refer to tears as pain
water to acknowledge that they are dealing with pain that's most likely in their mind. This is also not to be attributed to manly tears, though it is a similar bridge to that and tears from sadness.