Tristan and Isolde: so amusing! Wait, what?

I saw L'Elisir d'Amore at the Met today (matinee performance). It never really struck me before seeing it that Adina must have stopped reading her story halfway through. The 'Tristan loved Isolde, but she didn't love him so he got a love potion' bit is different than most versions, but I think none of them could be described as "amusing"!

ps - what is it with all the stories that essentially say if a man loves a woman, she's obligated to love him back, or else be branded cruel and heartless? One of the nice things about this opera is that Adina actually calls Nemorina out on that trope.