How we cite our quotes: All quotations are from Eternal Sunshine of the Spotless Mind.
Quote #4
JOEL: Uh, don't go too far. […] I think I should go back.
CLEMENTINE: Come on. Come on!
JOEL: What if it breaks?
CLEMENTINE: "What if"? Do you really care right now?
The ice is a metaphor for intimacy. Joel is afraid to take a leap of faith and put his trust in someone. If that someone breaks his heart, he will be left drowning in sorrow and regret… Or maybe it's just ice, and Joel's scared of bruising his bottom. Who knows?
Quote #5
JOEL: She's not looking at me. She's busy. She's not looking at me. No one ever looks at me. I want my mommy. […] Don't leave me, Clem. Oh my God, Clem.
CLEMENTINE: This is sort of warped.
JOEL: I'm scared. I want my mommy!
Baby Joel just wants to be noticed, like most babies or toddlers or whatever he is. Maybe Joel was actually neglected as a child, which might explain some of his insecurities. But most likely, he was just having a moment of fright when his mom went briefly out of sight.