Thanks for your replies and the references to Einstein crosses and rings - more for me to study! Okay, I think I understand better. However, saying that lensing is not so common can only be true from one vantage point, no? Ie. Earth. Because there aren't so many objects perfectly aligned with...
It's a question I've pondered over for years and I've even asked a few people but I've never had a convincing answer. As per the summary, if gravitational lensing is spraying light all over the place like an automatic lawn irrigator, is there any chance some light will do a tour of the universe...