Education is always more efficient when you're younger. Imagine the limit: if you have five years until retirement, spending them on training won't maximise you

Education is always more efficient when you're younger. Imagine the limit: if you have five years until retirement, spending them on training won't maximise your earnings! There are roughly 45 years in a career. If you do a PhD at 32 you only have about 30 years to exploit the degree.