Stuart Beatty's 5 Suggested Rules Of Screenwriting (Humor)
1. NO BOOKENDS
2. NO BOOKENDS
2. NEVER KILL THE DOG
4. SAVE THE KISS TO THE END
5. FEEL FREE TO DISAGREE WITH ALL THESE RULES.
"Save the kiss to the end" is a sacred rule. Break it at your peril.
Bookends are perilous but they occasionally work, when the "true" story is what's happening in the bookends, and the middle is a dream, vision, fantasy, etc., for instance in The Wizard of Oz, and Ed Rex, and to a lesser extent, the Princess Bride.