It's simple and easily overlooked. Water is absolutely necessary for our mind and body. We don't live without it--mentally or physically!
Dr Nedley shares a formula for determining how many ounces of water to consume per day.
Weight (lb)/2 = Water (oz/day)
Weight (kg) x 30 (ml) = Water (L/day)
Do your best to have fresh, pure water and be cautious of water substitutes and caffeinated beverages that can actually cause the body to expel fluids. You may need more or less depending on pregnancy, exercise, altitude, climate, and other medical conditions. Check with your medical professional if you have specific questions.
Here's something to try: Use magnets or post it notes on your fridge to track your cups of water. Purchase a large container to place in your fridge and refill it daily. Break it down into manageable portions (30 oz before breakfast, 30 more by lunch, etc.) Figure out when it makes the most sense to consume your water by. Don't drink a gallon right before bed when you're struggling to sleep. You don't need the joy of waking up repeatedly to use the bathroom!