Buggy arc: Luffy gets imprisoned by Nami because he was too naive, and incapacitated for some chapters.
Kuro arc: Luffy falls asleep under Jango's comand.
Arlong arc: Luffy does a "stupid" attack and as a consequence gets thrown to the bottom of the sea by Arlong.
Little Garden: Luffy gets stuck under a mountain by a giant, and then gets constantly fucked over by Miss Goldenweek traps.
Skypiea: Luffy gets swallowed by a snake and then gets a giant golden ball attached to his arm, both times getting him away from the fight.
Foxy arc: Luffy gets constantly cheated by Foxy because of his extreme naivete.
Water Seven: Luffy gets stuck between 2 buildings.
Impel Down: In an incredibly tense race against time to save his brother, he finds the time to fuck around with that Sphinx and starts playing whack-a-mole with Mr. 3 clones . . .
Do I even need to continue? That's Luffy, take it or leave it. In the end, he'll get shit done and that's it. 2 years of training weren't gonna change that.
And I'm starting to wish Oda never introduced Color of Observation. It pops up in literally EVERY discussion about fights or power levels for quite some time now, and it's just getting old. Having CoO doesn't equal being a freaking GOD.