Water consumption

Hi!!!
I'm hitting the gym 6 days a week.
I've heard from a "know it all" guy at work that drinking too much water is bad for you. I drink roughly 4L of water a day. Is this bad? If I'm thirsty, I believe I need water..

This is the first time I heard of this.

Yes, overdoing anything could be bad to your health. 4L water is nothing unusual in these parts of the woods, but you could die from drinking too much water. No, I'm not talking about drowning, I'm referring to water intoxication that happens when you are over-hydrated and your electrolyte levels are out of balance.

I read countless places that the rule of "8 glasses of water a day" should be thrown out the window.
Many say that you must drink water and you require it, e.i., when you're thirsty. If I'm at my desk at the office, I drink about 400ml an hour, so in the space of 8 hours, I drink 3.2L. When I'm at the gym, I drink maybe another 400ml, maybe less. When I'm home, I drink water which comes to about 500ml.
Some days I consume more, some less. Really depends if my lips get dry or not.
I hope this is normal..

You need to drink LOTS of water to actually cause any kind of damage to your body. I drink up to 8L of water on some days. Your muscles need water to transport the glycogen from the carbs you eat, and has many other functions.
So I would not take this "know it all" guy seriously at all.