Sure, you can still find a meal for $1 in plenty of places. But if you have anything approaching a normal appetite/metabolism, you will need at least six of those meals a day.
If you’re spending a significant amount of time in Europe, it’s almost inevitable that you will get on the wrong train at some point. Accept it and deal with it!
Yes, having a car is more of a headache than a boon when you get into the big cities, but if you happen to be road tripping across the country, weekends are actually best for visiting most major hubs. You’ll find cheap weekend parking deals in places like Boston, Chicago and San Francisco, but affordable weekday parking is nigh on nonexistent.