What to do when my instinct tells me one thing but my brain tells me something else?

Here's an example. I was in the cut off with 55 unopened pot so raise to 18c stakes are 3/6c. Only the big blind calls. Flop kq4 2 diamonds. He checks I bet 18 he thinks a tiny bit than calls. Turn q still 2 diamonds. Now he instant checks. Now I have zero history with this guy. HOWEVER I don't know why maybe it's how he reacted to everything but it FEELS like he's on some kind of draw. However he could easily have a queen a king and if he has a 4 I might get river value... Put it this way, if I didn't have any feelings on what he had apart from he's likely to have a pair or a draw, i would most of the time give him the free card on the river since it's more of a guess than anything... So my brain says checks but my instinct says bet... I decide to checks ( I actually ran out of time ), and the river comes a 9 of diamonds, he checked I check back he had a10 clubs, so I missed value on the turn... What do you guys think?

you played it well, you're not going to get 2 streets of value with 55 unimproved on a KQ flop very often.

or, he played it badly. not betting the river when you're on a draw is terrible.

I think I would have c-bet to protect my hand. He could have easily stolen that pot from you with a river bet and easy fold if he calls and bets river.

sounds like a perfectly played hand to me... not much you can do when overcards flop against a limp/call, especially when the board has straight and flush outs. lead out on the flop, make your hand look strong by hollywooding a bit, and check check... playing safe wins most of the time there.

It worked out for you, so I guess you played it fine. If you had bet the turn-say 30 cents, he probably would have folded, but if he does call you have a problem on the river. If you check the river now, he might make a decent size bet on a bluff and you are very hard pressed to call it. You might fold and now you lose the hand instead of winning. So I'd say you played it fine.

I think you played it fine, you don't necessarily want to get into a huge pot and you showed some pot control and won with what you thought was the best hand, and it was.

I know what you are talking about, a lot of times these type of situation happened to me. I know that, sometimes, I'm doing the wrong play, but my instinct are telling me to do the play. I have to say that 50% of the times, I follow my instinct and do the play if when I know that I'm behind before see the rest of the hand.

What did you think his range was when he checked the turn? And out of that range, what would he have called with if you had bet while still leaving him without enough to beat your pair? Probably not a whole lot, which means that you didn't lose a lot of value. It's not mathematically optimal if he would have called even a small percentage of the time, but it does seem thin enough that you probably have aspects of your game that have substantially more potential to improve your win rate. I have bigger leaks for sure - and that's just considering the ones I'm aware of.