This happens when they already know there is a fair chance that you are human. So they give you an easy one and get their OCR for free. You are probably already

This happens when they already know there is a fair chance that you are human. So they give you an easy one and get their OCR for free. You are probably already logged in your Google account when it happens. Go incognito, browse with Tor, etc. and you will get the impossible ones.