So, today I played my first real money tournament against real poker players, and against them, the reasons not to limp are way more obvious than online or against buddies.
$40 buy in with rebuys, 27 players, I finsihed 11th with no rebuys, so can't feel too bad about that. Early on I got a few lucky hands and played agressively and my stack rose very quickly from 8000 to about 20000.
Then came the slow decline. For about an hour and a half only twice did I ever get any hand that's even on the beginner's hand chart, 89s and A7s, both when I was out of position. With the 89s I made the beginner's mistake of deciding to play a drawing hand then forgetting which cards I had, so then when I took a second took it became obvious to the sharks I was drawing and a guy with a pair of sixes bet pot size. With the A7s I succumbed to temptation to limp, I was on the button, and then the BB raised all in. As the blinds rose my stack depleted.
One time I was BU with K8o with no callers, 6 people at the table, and a BB I saw bet big with trash hands, I probably should have bet that hand since I was so short stacked, just to convince my competitors I wasn't a rock and was just getting a long series of really terrible hole cards.
Now I'm really short stacked, I go all in with A8o, everyone folds, thinking of course I probably have KK because I folded the last 30 hands.
Finally I got JTs, the best hand I'd seen since very early in the tournament. Somebody bet enough to force me all in, I call. He reveals AK. Flop gives me my Jack, turn gives him his King, I'm out.
There were people at the table who did seem to know exactly what I had every time I showed aggression, and it was only the loose passive players who were there at the beginning I was initially able to profit from. This has been a learning experience as to exactly why I should behave the same way for any hand I want to play.