And I wasn't merely implying fortification. But that Jägermeister is fun to pass around and break the ice with new folks you meet and need to get along with for a short time anyway. I don't know where it comes from, but I was in such a couchette when someone stepped onboard somewhere and brought out a big bottle of Jägermeister and taught me this trick on a long overnight train ride all the way across Germany. It was more fun this way for sure!
I applied a variation of this trick in France myself, with wine. On a long day's journey with French rail, I couldn't afford to pay their high price for a tiny bottle of water, and I really needed to drink more water that day. It was hot and I was on the train for hours and hours. I survived, but it wasn't so much fun. On the way back, I had to change trains at Gare Noord plus I had a little extra time. So I went to the grocery store across the street and bought about 2 liters of water, a similar-size box of wine, and a staggering amount of disposable plastic drinking cups which cost about 59 cents; the total was like 4 euros. That's about the cost of a tiny bottle of water on French rail. French rail wasn't making any sales of wine or water off anyone, seated anywhere near me in those tiny TGV 2nd-class seats.