On a side note, I find it unlikely that these three sentences simply popped up in your mind. The kind of things that just "pop into your mind/head" are "Ooooh, I must buy teabags!" or "I wonder why giraffes are so tall". They're the kind of thoughts that pop in and pop out again - very fleeting. The sentences you came up with sound like you sat down and thought them up on purpose.
Student or Learner