Is there anything in vg that took you way too long to realise?

Like the title said I am curious on what silly things that you personally have realised that took way longer than it should have?

For example, Hope on Damp. As a DP player I have only just today realised that while under Hope On Damp a DP Player can call as many of their G3s to GC as long as they make that 20k shield restriction (not counting the G3). This is because the G3 has 0 shield in hand.

This does also mean you can't just call a G3 because it has to meet the restriction while in hand. (For example you can drop 2 10k shields + X amount of G3s, however you can't call a G3 that will have a 20k shield because it doesn't have that while in hand)