ha, yes i think all of these have happened to me.
and i'm only 19.
i also frequently just cannot find the word. I can think of any other word in the world, except the one i want. Most of the time, even definitions or synonyms for the word i want-but it drives me nuts, cause i know these other words are completely fine- but it just isn't the one i want!

hmmmm..... i'm trying to think of others-cause there are definitely many of them- i just can't remember