"Why do I keep losing?!"
- Your opening moves didn't correspond with your strategy.
- You weren't paying attention to your opponent's most recent move and what it does.
Example Game (1)
In this game you saw a great opening for both sides, except the order in which it was done.
The best opening moves to arrive in this position (a very common one even for GMs) are;
1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. Nc3 Nf6 5. 0-0 0-0
It is okay if you don't start in this same position every game, most IMs and GMs play different defenses and openings each game!. You might be wondering why does it matter? Well the answer to that is if your strategy is to Scholar's Mate your opponent, (1. e4 e5 2.Bc4 Bc5 3. Qf3 Nc6 (or Qh5) 4. Qf7#! (not a great idea if your ELO is above 600) it's obviously not good to start with Nf3, it blocks the Queen from the F3 square and the H5 square. So basically play your opening moves based on how you want to win the game.
Example Game (2)
Here it looks like such an innocent position for white, and it is! But if you notice the white knight is under attack by the bishop and in this position you don't want to lose a knight. So black attacks the queen with the knight, expecting white to waste a move by moving the queen. Except.... white blunders the Queen by attacking the bishop with the knight!! Pay attention to what your opponent's move does to you!