I have often heard that "a foul is a foul, even in the penalty area". But I do not hold that view. Considering the very high possibility of a goal-- perhaps a game winning one, I posit that a foul that one may call away for game control purposes is NOT necessarily of the caliber to award what may well be a game winning goal. In other words, a minor foul outside the box could be considered trifling inside of it. Agree? Disagree?
I think most adhere to this concept, but I've always explained it in writing a bit differently: A foul is a foul everywhere, including in the penalty area. But sometimes you have to call otherwise trifling fouls at midfield for game control purposes. So it's not that real fouls suddenly morph into trifling fouls due to the boundaries of the penalty area. It's that you select a wider range of fouls to call, including trifling ones, outside of the penalty area. Semantics that result in a distinction without a difference, but it's a distinction that makes a lot of referees sleep easier at night.
This is an area of much confusion: First and foremost, inside the penalty area a foul is a foul is a foul, if it has any effect on play. Put a period there. Outside the penalty area a foul is sometimes not a foul if there is little or nothing to be gained by stopping play, and not-a-foul sometimes IS a foul if there is something to be gained by calling, but doing so does not disadvantage the team that commited the not-foul.
I don't like the ticky tack fouls called on the offense in the 18 yd box. If they were to call these same fouls on the defense you'd have more pks than you can count. And so to be fair & consistent the refs shouldn't call so many fouls on the offense, it puts the offense at such a disadvantage in the box. It's already hard enough to score and yes, I remember Ballack getting away with a push in the back in Euro 08, but that was an exception to the rule (it wouldn't have been called on the defense either). The defense pushing an offensive player in the back while in the box hardly ever gets called, but the offensive player doing the same will most likely get called. I can understand blatant fouls and protecting the goalie, but I think they go a little too far. Most goalies have a size advantage, made greater by being allowed to use their hands.
The second part is not great advice. It is espoused by someone believing himself to be clever. As you get older, you'll understand why.
I think part of the problem in this discussion is the assumption that contact is a foul only when the referee blows the whistle. That may be the way that we normally think about it, but even slight contact may be a push or a kick of an opponent, et al. Then we have to decide if that push was trifling or doubtful. Even if it's trifling, it's still a foul, just a trifling foul.