For my 40th birthday my husband took me to dinner with a couple we'd been friends with for years and gave me a nice gift. I thought that was just fine. Several weeks later we received an invitation to a surprise party for another friend.  We were instructed to bring no gifts and keep it a secret.  When the guest of honor walked in the front door, we all began singing "Happy Birthday".  When we got to "Happy Birthday dear Gregg", I sang that while everyone else suddenly looked at me and sang "Happy Birthday dear Gina"! The joke was on me!  They were actually celebrating my 40th birthday weeks after the fact! I was speechless!  It was the biggest surprise ever!