What's the worst beginner advice you ever received?

"Risk 10% a trade, grow fast", "add to losers so your average improves", "stop-losses are for the weak", "this robot prints money". Bad advice sounds plausible when you're new, and it survives because it flatters impatience.

Share the worst advice you followed or almost followed:

• the advice, and where it came from
• what it cost you
• the correction you'd give a beginner now

This thread could save someone's first deposit. Keep it civil and specific.