I use to forgot to drink water all the time. This has affected my health in irreversible ways.
In 2014, after a week of me drinking soda with very little to no water, I got sick. No surprise I know, but I had no idea that I was dehydrated. Dehydration didn't even come to mind. By the time I figured out what was going on it was too late. I was in the hospital with a kidney infection after having a back spasm. I could not sit up without feeling like my spine and nerves were ripping out of my back. It was the worst feeling I have ever experienced. Now if I don't drink enough water I can't walk from A to B without being in pain. The good news is now I drink more water.
Don't wait till it's too late to take care of your body.