The show would be five minutes long if they didn't have Barry keep letting villains get the drop on him.
I used to read comics and wonder why Superman or Flash doesn't just charge at a villain using superspeed and punch them in the face 50 times before they have time to blink. Like the comics you sort of just have to go with it and turn your brain off.
I think they can do better, and they have in certain episodes.
- Weather Wizard I, he was totally new.
- Being overwhelmed by Multiplex's numbers made sense. In the warehouse there weren't enough, but he was very new, and hypoglycemic and it made sense.
- Kyle Nimbus was made of gas. Hitting him was pointless and dangerous. Nice.
- Plastique wasn't a villain, Barry touched her, lost that conflict, but went easy on her from then on
- Tony Woodward could take a punch. Having the shelf fall on Barry was dumb though, but the idea of being surprised by a wall wasn't impossible.
- Farooq was using something very fast - electricity. I don't remember the confrontation, but being electrified should be a problem for Barry.
- Rainbow Raider didn't make much sense either, Barry was being super dumb/overconfident, especially knowing that others had been affected somehow. The fight with Arrow only made sense in the light of the idea that Barry was somehow holding back that Arrow got through to him before he caught that last punch.
- Reverse Flash makes perfect sense, y'know?
- Captain Cold doesn't make much sense. In his first episode, Barry could still have chased him down after that guard died. He'd have been mad too. I think that's one of the weakest parts of the series' use of his powers, that he never chases down people when he could. It only gets worse with Heatwave and Golden Glider, the showdown in the street where Flash runs past them as they spray guns everywhere was absolutely ridiculous. A couple snipers could have fixed the problem easy peasy. This is Johns' silver age addiction hurting the show. They need powers to compete with Flash. Even with the "New Deal" that Snart and Barry made, it's doubtful Barry can't disarm them.
- Pied Piper was smart, got captured, as he should, part of the plan, as was awesome.
- Peekaboo was a teleporter and though Barry didn't knock her out like he could have, it kinda makes sense for him in a way. Also, the boyfriend getting the drop on him with a bullet make sense.
- Firestorm he was taking it easy on
- Eiling with his endless boxes behind the back made little sense. You don't have underlings for that stuff. Ugh.
- Weather Wizard II was legit. But then they upped the ante, showing he can dodge lightning and grab people and drop them in jail before they know what's happening, which made the ensuing conflict with Captain Cold pre-deal so weak.
- Trickster was good, until they found out that Axel was at Iron Heights while Barry was downtown. It would have taken no time for him to get back and still catch the Tricksters. He was highly motivated too, IIRC.
- Barry being 'trapped' by the robotic Bees was ridiculous
- Everyman hitting him with a gun was dumb from both sides. He would've just shot him, like those cops. Barry recovers faster from fractured bones than he does getting hit in the back of the head. Silly.
So yeah, there's only been two or three 'powers forgetting' moments outside of the conflict with the Rogues, and now even that has a little plausibility with the deal, though there's still little reason for him not to just disarm them all when he sees them.