Blockchain 101: Wallets, Keys, Chains

I'm considering a "Blockchain 101" course that covers: hashing, signatures, building a toy chain in code, wallets and private keys, how Ethereum accounts and gas work, sending a real testnet transaction, writing your first Solidity contract, and basic custody/security.

Here's my situation:
1. My background is: [e.g. "backend engineer", "product manager", "student", "curious but non-technical"]
2. The reason I'm even looking at blockchain is: [e.g. "friends invested and I feel dumb", "my company is exploring stablecoins", "I want to build something", "I just want to understand the news"]
3. I've already tried to learn about blockchain by: [e.g. "reading one article", "nothing", "I've bought crypto but don't understand it"]

Answer these directly:
- Is "learning how blockchains actually work" likely to help someone in my situation, or is it a dead end? Be blunt.
- Name 2 real use-cases in my life or field where understanding the mechanics (not just the price) would matter.
- If I finish this course, what could I realistically build or do in 30 days that I can't do today?
- What's one reason someone like me might regret spending 25 hours on this? I want to hear the downside, not a pitch.