nonperfect forms with since

[Tdol]

You would be totally surprised what you can hear from native speakers in an informal conversation!

That's normal in speech- as we're changing our thoughts, moving around, hesitating, forgetting what we've just said, repeating ourselves, etc, we say all sorts of things. Speech is more fluid- I could say I've been there...last week, but I wouldn't write it- it's simply that I said something, then added another which is fine in speech, but would make it wrong in writing.

 

[philo2009]

It's probably because I have known this song ("Don't Bother Me" -

The undeniable musical brilliance of George Harrison notwithstanding, inferring rules of English grammar from pop songs is, at the best of times, a hazardous undertaking!!

;-)