After Steve and Myra survive a near-death experience, he realizes how much he really cares for her and decides to give up chasing Laura (for now, anyway) and let himself love Myra. He then gives her his Science Club Pin, and they kiss.
And the reason why they're in Russia and he isn't? In a previous season they abandoned him for a research project. That episode ends with the Winslows agreeing to look after him while they're gone.
Eddie letting Waldo know, in no uncertain terms, that they'll always be best pals no matter where they go after high school.
Waldo discovering that he is an excellent chef, which gives him a chance to be more than just the neighborhood idiot when he goes off to culinary school.
Waldo's defeated, repeated, "Aw, gee," when Maxine mistakes Eddie's messing around to mean that Waldo is too, and you see how broken up he is when he thinks the girl he loves hates him.
Eddie accidentally throws one of Laura's cherished dolls away, so Steve spends all of Christmas Eve looking for it at the dump. He finds it with the help of a dog.
Carl shows up for Steve at school when his own dad wouldn't, and Steve, in surprise, responds with "BIG GUY!" and glomps him.
Steve starts a drive to save a classmate of his who has leukemia, despite the fact that the guy is always bullying Steve. At the end, the classmate thanks Steve and offers to buy him lunch.
In one episode, Steve plays poker with Carl and his police pals. He initially loses badly to Murtaugh and didn't know they were playing for keeps. Carl gives Steve his own money to make him happy, but the nerd decides to get back in the game and get back at Murtaugh. He wins, even taking Murtaugh's prized watch in the process, but he opts to give it back.
Steve: I play for fun. Murtaugh: You're all right, kid. (salutes him)
At the end of the episode, Carl and Steve opt to cut the cards for a little bet. Steve has to stay away for six months if Carl wins, but can come over whenever he wants if he wins. Steve draws a three. Carl then draws, and he (and the audience, but not Steve) see that he's gotten a face card, but he tells Steve it's a two.
In the Gun Safety episode Steve despite normally being a coward, has the guts to stay by Laura's side so she didn't have to go to school alone when a bully threatened her with a gun the day before.
Upset, 3J hides out in the Winslows' attic. When they find him, they announce that they want to be his foster parents, and will speak with his case manager. Before he goes to share Richie's room, he hugs Carl and Hariette.