Having lived in Canada for three years, I had the opportunity of getting used to the metric system. Let me tell you, it sure makes a lot more sense than English measurements.
Distance: The speed limit in Canada is 100 km/h. Toronto to Detroit is 450 km and instantly you know that it's 4.5 hours away. That's a lot easier than dividing 450 miles by 60.
Weight: If a recipe calls for 400 grams of flour and you want to triple the recipe, boom, 1.2 kilos. Now try tripling 10 oz. of flour and telling me how many cups and ounces it comes to.
Temperature: Now here is one example where Fahrenheit makes a little more sense. You see, Mr. Fahrenheit developed the scale by noting the coldest and hottest that it ever got in Amsterdam over several years. He marked the coldest at zero and the hottest at 100. So, it most Western cities, zero is the coldest it'll ever get and 100 is the hottest. Anything below or above that is an extreme. Works pretty well. However, zero F is practically balmy in most of Canada. Snot freezes pretty quickly at minus 25 C while waiting for the streetcar in Toronto.
Liquid Measurements: Again, cooking is much simpler this way. Tripling 200 ml is a lot easier than tripling 2/3 cup. For my mind anyway. Gasoline is sold by the liter. At $1.35 a liter, it'll cost about 45 to 50 bucks to fill up that Honda Civic.
Getting used to the Metric system: Bottom line, DON'T convert. Just get used to knowing what 15 C feels like. Learn how much 500 g of slice pastrami is. "But what is 15C, Americans will say." Well, what is 50 F? Again, don't convert! That way, during your first Winter when it's 25 kilometers below zero, you'll know that it's going to take a while to shovel those 15 liters of snow away.