These all follow the SVO order: Subject Verb Object. You can see this by asking each as a question: The last thing I remembered was WHAT? kissing my girlfriend. The only thing I can do is WHAT? Ask for help. The first thing I did was WHAT? Doing the dishes. So in each case, the words kissing my girlfriend, ask for help and doing the dishes are verbal phrases being used as direct objects. Although the third one should be The first thing I did was to do the dishes. The way you wrote it is wrong.