One year, my husband was working night shift. I spent 3 days blowing up balloons and hiding them in my kid's closets and under their beds. About a million were stashed in the garage. On his birthday, while he was sleeping, I snuck in and put all the balloons on the floor of the bedroom. Our bedroom is pretty big and they were about 3 feet deep in there. The kids couldn't wait till he woke up and got out of bed into the sea of balloons! He wasn't super thrilled, but since I have a latex allergy, he did realize the effort that went into it. We had balloons floating all over the house for weeks.