Wisteria in flower again!

Yes, that well-known spring-flowering climber, beloved of country cottages, is at it again: What is going on with our gardens these days? Is it climate change? Are the seasons really no longer predictable and "set", as they used to be? Or are we just remembering things incorrectly, in the same way that we all look back to our childhoods and remember long hot summers, when it didn't rain... oh hang…