when the application hasn’t used lambda expressions before, even the framework for generating the lambda classes has to be loaded (Oracle’s current implementation uses ASM under the hood). This is the actual cause of the slowdown, loading and initialization of a dozen internally used classes, not the lambda expression itself.
assigning the values of instance variable initializers to the corresponding instance variables, in the left-to-right order in which they appear textually in the source code
X. Glorot, and Y. Bengio. In Proceedings of the International Conference on Artificial Intelligence and Statistics (AISTATS’10). Society for Artificial Intelligence and Statistics, (2010)