What are the lessons of Venezuela?

1. Don't put all eggs in one basket. Diversify your income sources.
2. Spending should correlate with productivity.

Venezuela's current state of disaster is due to many aspects. But I will pin down on two major issues.

All eggs in one basket. This was probably the biggest mistake by Venezuela. PDVSA, the state-owned oil company was one of the biggest exporter & source of income for the country. But apart from that, the country did not have any major industry. They did not work on diversifying their income portfolio. This was their biggest mistake since when the oil prices dropped the entire country went downhill. This is what I call the blackberry effect. (By the time blackberry realized the advent of touch phones, it was far behind to catch up and nearly at the point of no return. Summary: Realizing a reality too late to do anything about it.) So when shit hit the fan, the country did not have any alternate industry state-owned or private to sustain.

Spending: Socialism is an expensive lifestyle and has high costs for the government. Venezuelan government created jobs just to offer employment, with no real added productivity, simply to increase the employment rate. Increase in cost that does not correlate to productivity. This will in long-term create an imbalance.