Not ridiculous but great advice. For those who don't like numbers, the can be non-numerical. Just get up earlier a few days before your trip to Europe, which means going to bed earlier. Then in Germany, get up from bed a little later. That reduces the time difference in your body.

Example (for the people who like numbers)

If no adjustments to your schedule
Day 1 sleep in NYC 11 pm - 7 am
Day 2 sleepless night on the flight to Europe
Day 3 11 pm in NYC is 5 am in Germany. In other words, when it's 5 am in Germany, you'll start to want to go to bed. When it's 7:30 am in Germany and your alarm rings, you are zonked.

If you adjust your schedule slightly
Day 1 sleep in NYC 8 pm - 4 am, having done this for a few days
Day 2 red eye flight
Day 3 sleep in Germany at 1 am - 9 am, having a schedule that allows you to get up at 9 am. 9 am would be 3 am in NYC, which is only getting up one hour earlier. Presto, less jet lag. Maybe none if you're young.