I just realized…
I am watching Season 2 Episode 15 The Maternal Capacitance, the first episode Leonard’s mom makes an appearance, Leonard is serving her tea and she goes on a checklist of how her tea is to be served and Leonard fails at this, obviously. Tell me why I just realized that this is Sheldon’s exact behavior and since Leonard clearly has mommy issues, his attachment to Sheldon is now obvious to me. 😭 I always just thought he felt bad for him at first and he obviously loves him later on but Sheldon was an unconscious substitute for his mom.