My heart leaps up when I behold
Emotional Geography
Notice the verb 'leaps' — this is not just seeing, but a visceral, physical response to natural beauty.
Existential Choice
Dramatic ultimatum: experiencing natural beauty is so essential that without it, life loses meaning. Wordsworth would rather die than lose his sense of wonder.
Childhood Memory
The line suggests childhood perception is not lost but preserved. Wordsworth believes early wonder is a permanent state, not something outgrown.