Not to be a total f'ing geek here, but by the end of that episode, he was impressed with the future. Said it was worth giving up cigars for. Great performance by Jerry Hardin as Twain in a sillier than usual time travel episode.
Take notes. Show work. Draw pictures. Physics can seem hard, but really, it's very procedural (unless you’re taking an advanced Physics class in college). If you really pay attention to the way your teacher/professor does the steps, you will succeed.