This is just my general belief, but I'm seeing a lot of AA hands being posted lately. I can see how AA would get into tough spots often because you're tempted to go farther with them than other hands, but in terms of improving your game I think focusing on more marginal spots/hands would be much more beneficial.

Think about spots where you can open up your game and still be profitable. Spots where you can steal wider, or defend looser in the blinds that are +EV. Spots where you can peel flops IP profitably that you might not be doing now. These are the types of spots that come up ALL THE TIME, and will make a difference to your winrate. AA is a rare hand to begin with and the times you get into trouble spots with it even more rare, so I don't think these spots are that make or break.

That could just be me though.