Bring a large pot of salted water to a rolling boil and cook the spaghetti until just al dente, about 8 minutes. Reserve 1/4 cup of the starchy pasta water, then drain and set aside.
While the pasta cooks, heat a large skillet over medium-high heat and add the olive oil, letting it shimmer. Toss in the finely chopped garlic and sauté for about 30 seconds until fragrant and golden, filling the room with a warm, aromatic scent.
Add the shrimp to the skillet and cook for 2-3 minutes per side until they turn bright pink, slightly charred, and tender. Remove the shrimp with a slotted spoon and set aside.
Reduce the heat to medium, then add the drained pasta to the skillet along with the red pepper flakes. Pour in the reserved pasta water and lemon juice, tossing everything together for 1-2 minutes until the sauce coats the noodles with a glossy, fragrant sheen.
Return the cooked shrimp to the skillet, gently tossing to combine. Taste and adjust seasoning if needed, adding more lemon juice or red pepper flakes for brightness and spice.
Sprinkle the freshly chopped parsley over the pasta, giving everything a final toss. Serve immediately, garnished with extra lemon wedges and parsley if desired, allowing the aromas of garlic, lemon, and seafood to fill the room.
