For me, it's how scary it feels to love my child so much. Whoever said becoming a parent is like living with your heart outside your body (or something like that) was spot on... I've never felt this vulnerable in my life. Every day I fall more in love and every day I struggle with at least some anxiety about something happening to her. I do trust the caregivers at her daycare, but it's HARD entrusting your whole world to relative strangers! Anyway, I guess that is both the best and most difficult thing for me. What about for you?