I don't know if - My friends said I don't know, so I added it to the dictionar

My friends said I don't know, so I added it to the dictionary. Why? Because I'm dumb and they're smarter than me.

I don't know if I should ask her out. My friends said I don't know, so I'm just going to stay single.

I don't know if I should eat the whole pizza. My friends said I don't know, so I ate it and regretted it.

I don't know if I should take the test. My friends said I don't know, so I failed and cried.