Worst "oops" moments in PBW?

[LGM]

I am in the top 3 of the 3 games I am in, but that doesn't mean I don't make mistakes. One of those games I commited one of the following. The rest were mistakes in prior games:

1) Forgetting to change the default strategy for ships to target Closests. This can cost you battles quickly as all your long range shots fail to hit anything.

2) Hitting the 'withdraw from game' link instead of 'undo turn' in a PBW game.

3) Building Minelayers and Satellite layers (two separate designs the same turn) without engines. Retrofitting is of no use unless you have a Resupply facility there as well. I have always liked how shipyards can supply a new ship, but not a retrofitted one. In this case, I ended up scrapping the ships and rebuilding them because it was faster than grouping them in a fleet to resupply. A little costly in resources at a critical time for my empire though, but time was a bigger issue.

4) Upgraded ship engines at a site without a Resupply facility. I did several ships of the same design the same turn. Lots of ships were stranded until I could fleet them with a buddy to go to a Resupply base.

5) Forgetting to uncheck 'split research evenly' the first turn of a game.

6) Forgetting to allocate research the first turn of a game.