Reverse engineer 2025. How to plan realistically?

Hey everybody. Happy new year, new goals, new plans! 🗺️Story: I’m use to detailed reviewing the year that has past and building a very thorough annual plan according to what I want to archive in the next 12 month 📈 … And then reverse engineer monthly and building a weekly plan from that. ❌ But my problem: ➡️ I’m always overestimating how much I can do in a week. When building things from scratch, it’s hard to know precisely how time it’s gonna take. And this pushes the whole plan. I’m pretty sure I achieve MORE when I do this, but it still feels like I’m constantly failing. 🎤 Do you have any tips, tricks or ways to set REALISTIC plans based on goals in a fixed timespan? TL;DR: What’s your best tips to setting realistic plans/goals