Ever since SH1 I've been in the habit of running several careers at the same time, one from each available command. With SH3 I start with one each from the 1st, 2nd and 7th flotillas. My problem isn't that I get bored, but that every time somebody comes out with a great new mod I feel the need to start over and use it from the beginning. This means I've never progressed past mid-1940, which means that even though I've owned SH4 for six years now I've never actually played an American campaign.
We all have our little foibles.