MettaurWARNING! The following is a nerdy interlude into the series of events depicted above.
I saw one episode in which Aniken was obsessed with r2-d2, even risking the entire rebel force to try and rescue it. It was stupid, and slightly creepy.
Anakin was obsessed with getting back R2 because he had vital information with regards to the Republic's deployment, numbers, missions, and other such vital data which in the hands of the separatists and Grievous would have crippled the Republics war effort.
PPActually, Obi-Wan was, to an extent, aware that there was something between Anakin and Padme, but Obi-Wan never thought much of it because he too had fallen in love as a padawan. In fact, he actually forsaken the jedi order temporarily for the girl, but Obi-Wan came back (and Qui-Gon decided to keep his little quitting a secret).
This is what forced Anakin to enter a secret marriage with Padme which caused him to hide critical things about his life from Obi-Wan