What looks difficult but is in fact easy

A request from Nels:

My 8 year old daughter was bemoaning the fact the things that look simple are often difficult. Then she turned to me and asked what things look difficult, but in reality are easy?

When I was ten years old, I thought that "paying bills" was going to be quite difficult.  I don't mean generating the income, but rather the literal act of paying the bills.  I didn't understand how you would find out where to send the money and also how to keep track of it all.  It turns out that the suppliers make that fairly easy for us.  They hook up service, or send the magazine, and then they send you the bill.  They keep track of it for you.  I hadn't read Adam Smith yet. 

That said, I'll pay months of a bill in advance to avoid having to deal with it.  I can never tell when I have renewed a magazine or not and I puzzle over the game-theoretic problem  (how many renewal notices should they send, and do they send, given my rational response is to ignore them for a while?).  I probably could not balance a checkbook. 

So was I wrong in the first place?  Maybe it is really hard!

Which is why I find this question difficult to answer.  Even though it looks easy.