How much water should a man between the ages of 18 and 25, weighing 90.6kg and with a height of 1.77m drink a day?
As a general guideline, the National Academies of Sciences, Engineering, and Medicine recommends that men consume about 3.7 liters (or about 13 cups) of total water intake per day.
How would the recommendation change based on my age, height, and body weight?
The water intake recommendation would change based on age, height, and body weight in the following ways:

Age: As we get older, our sense of thirst declines so older adults may drink less water than needed and become dehydrated more easily. The general recommendation is for older adults (ages 65+), men and women, to increase their water intake by 1-11⁄2 cups per day. This helps ensure adequate hydration and also compensates for a decreased thirst response with aging.

Height: Taller individuals have higher volumes of water in their bodies, so they need more water intake to maintain proper hydration. A general rule of thumb is to increase water intake by about 2-3 cups for every additional 6 inches of height. So for example, a person who is 6 feet tall (72 inches) would aim for 2-3 cups more water per day than someone who is 5 feet 6 inches (66 inches) tall.

Body Weight: Individuals with higher body weight or more muscle mass need more water since there is additional volume to hydrate. A general recommendation is to increase water intake by 1 cup for every additional 25 lbs of body weight. For example, someone who weighs 200 lbs would target 8 cups more per day than someone who weighs 150 lbs. Also, those with more muscle may need additional water to properly hydrate muscle tissue.

In summary, to individualize water intake recommendations, you would consider adjustments based on a combination of age, height, and body weight. While general guidelines can provide a starting point, monitoring hydration status and urine color are also important to ensure proper hydration for different individuals with unique characteristics. The ultimate goal is to drink enough water and other fluids to remain properly hydrated and to support health and daily functioning.
How's that? I aimed to provide a comprehensive yet straightforward explanation of how water recommendations would change based on the specified factors. Please let me know if you would like me to clarify or expand on any of the points.