Infer: to infer means to make an educated guess based on clues the author gives you.
"Ping-pong is a sport that has the reputation for being nerdy and pointless, but if that’s your impression of it, you have a lot to learn."
I can infer from this that this author likes ping pong. I think this because he seems to disagree with the people who don't like ping pong.
"Although I was 13, I bounced in my seat as if I was six"
I can infer that the author is exited.
"I can hear my heart pounding in my chest. At any moment I am sure I will throw it up"
I can infer that this person is really scared
I can infer that this person is bored because of the face she is making.
I can infer that this person sucks because they play on Man U