How far off can my read be?

The other day at the Rio I was new to the table, sizing people up. After maybe 30 minutes, I thought that a 30-ish guy at the far end of the table was going to be a solid, tough opponent. He was kind of awkward in handling his chips and cards, so I knew that he was new to casino poker. However, his decisions seemed confident; he wasn't overly loose; he continued aggressively once he took control of a hand; and opponents seemed to give him a lot of respect. He was quiet, moved and talked very little, unflappable, showing little of any emotion about anything. I pegged him as a pretty experienced online player, making good poker decisions, but just inexperienced in the mechanics of live poker. This was somebody to watch out for.

Then came the hand that opened my eyes.

I had A-J in the big blind. Mr. Confident raised from middle position, got one late-position caller, and I joined in the fun. The flop was K-Q-10. I had flopped the joint, the Broadway straight. I checked. True to form, Mr. Confident put in a $20 continuation bet, and the third player called. I check-raised to $60. This was about half of my stack, which presumably signaled to the other players that I was perfectly willing to go all the way here. With little hesitation, Mr. Confident called, making me think he had either two pair or had flopped a set. The other guy folded.

The turn was a blank, and of course I shoved the rest of my chips in. Mr. Confident quickly said, "I call." I showed my straight. He kept his cards face down. The turn was a jack, which I hated, because if he had A-K or A-Q, he just made the same straight that I had.

But then he turned over... K-4 offsuit.

Yes. K-4 offsuit.

Raising with K-4 isn't totally crazy if it's an unopened pot, though doing so in middle position rather than late position is a bit iffy. You have to know that you're making a play based on table image and representing something stronger than what you really have; you do not want to go to a showdown, unless you happen to hit a truly miracle flop (like K-4-4). When you flop top pair with it, and the action is checked to you, a continuation bet is perfectly reasonable. But when you then get called in one spot, and check-raised by one of the blinds--who is putting in half of his stack and is therefore committed to putting in the rest--and you still have the third player to act on the check-raise behind you, it is absolute suicide to do anything other than run away as fast as you can. You're done. The jig is up. You got caught with a mediocre hand, and you have to abandon ship.

But this post isn't to poke fun at how badly he played. It's primarily to marvel at how wildly off my initial assessment of him had been. I thought he was savvy, when actually he was clueless. I thought he would show me KK or QQ or KQ, when actually he was much, much weaker than that.

So how I have to ask, where does one go to get one's poker radar repaired? Mine seems in need of some fine-tuning.