Sci-Show Psych shares some insight on why you’re not always good at predicting what will make you happy.

If you had to guess, you would say that the person that knows you best is you. But knowing your future self is hard.

This becomes a huge problem since when it comes to moral decision making, most of us are consequentialists (even those who try to hide it). So if you can’t accurately predict the consequences of your choices — if eating that entire pizza at 2am brings less long-term happiness then you predict — it becomes difficult to make good choices. Really that’s the shortcoming in most moral systems: not an inability to agree on what to value, but an inability to agree on predictions about the consequences of various alternatives. Most moral disagreements aren’t about values, they’re either about facts, or about difficult predictions.