Sure, here are some clever and lighthearted comebacks you can use in various situations:
When someone says you're weird: "Thanks! Normal is overrated anyway."
When someone comments on your appearance: "I know, right? It's tough being this fabulous."
When someone calls you a know-it-all: "I prefer the term 'intellectually gifted.' But yes, I do know a lot!"
When someone says something sarcastic: "Oh, please, tell me more. Your sarcasm is just so refreshing."
When someone tries to bring you down: "I don't need your negativity; I have enough sparkle on my own."
When someone calls you lazy: "I'm not lazy; I'm just conserving energy for more important things."
When someone questions your choices: "I'm living my life, not auditioning for your approval."
When someone calls you stubborn: "You say stubborn, I say determined. Tomato, tomahto."
When someone accuses you of being too optimistic: "I'd rather be overly optimistic than endlessly pessimistic."
When someone says you can't do something: "Watch me prove you wrong."
Remember, comebacks are meant to be light-hearted and playful. It's important to gauge the situation and the relationship with the person before using them. Always prioritize being respectful and considerate in your interactions with others.