What’s the thing people told you, you would absolutely need for your baby?

That turned out to be completely useless. Everyone told me I’d need this hi-tech bottle warmer. I think I must have spent about $60 or more and it gathered dust in my basement almost immediately.

I had way more success with a mug of water in the microwave than trying to heat bottles in that thing. What about you? What are your purchase regrets for babies and toddlers?