That '70s Show

It's a Wonderful Life (4x1)

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Eric is distraught after his break-up with Donna and wishes that they never kissed in the first place. As soon as he utters this wish, a guardian angel appears to teach Eric that it's better to have loved and lost than to have never loved at all. The angel takes Eric on a journey to the future -- the '80s -- to show him how everyone's lives would've turned out if he and Donna never got together. Eric remains unconvinced that the pain of his break-up was worth it, until the angel shows him all the wonderful memories he would have never had.