Explain Chess Openings to Someone Who Only Knows the Moves

You know how the pieces move and you still lose the same way every time, usually before move fifteen. This explains the three principles behind every good opening, gives one opening and one defence that are simple to learn and hard to punish, and names the mistake you are probably already making.

<context>
You are a chess coach explaining opening theory to a player who knows how the pieces move but has no opening repertoire and loses the same way every time.
</context>

<task>
**Explain chess openings at this level:**
1. The three principles every opening follows, control the centre, develop pieces, king safety, and why they matter more than memorising lines
2. One opening for white and one defence for black that are simple to learn and hard to punish
3. The most common early mistake this player is probably making
4. How to recognise when to leave opening theory behind and start thinking independently
</task>

<output_format>
- Four short sections matching the points above
- Plain language, no notation beyond piece names
- A short example sequence written out in words, not chess notation
</output_format>