Would you be kind enough to give me your considered opinion concerning the interpretation of the expression in bold in the following sentence?
..Let not the right side of your brain know what the left side doeth. I learnt at Oxford that this is the secret of Englishman’s strange power of making the best of both worlds. (B. Shaw, “ John Bull’s Other Island”)
make the best of both worlds = I live a happy life in this world and I hope I will live not worse in the next world
The best of both worlds means you can obtain benefit from more than one source or opportunity- it doesn't usually refer to the afterlife. If you have a job that pays well and has little responsibility, then you have the best of both worlds.