How do I keep a big raise from quietly inflating my spending?

The enemy is lifestyle creep, where each income bump is fully absorbed by nicer everything until you are earning far more but saving no more. Beat it by automating the increase into savings and investing the same day the raise lands, before it becomes part of your visible cash flow. Set a rule such as saving a fixed share of every raise, then consciously choosing one or two upgrades that genuinely improve your life rather than upgrading across the board by default. Track your savings rate, the percentage of income you keep, and aim to hold it steady or rise as you earn more. Reviewing this at an annual check-up keeps you honest. The point is not to deny yourself, but to make lifestyle growth a deliberate choice instead of an automatic default.