Consistent with previous research, a study published in Nature Neuroscience reports that caffeine enhances memory consolidation.
“We used post-study caffeine administration to test its effect on memory consolidation using a behavioral discrimination task. Caffeine enhanced performance 24 h after administration according to an inverted U-shaped dose-response curve; this effect was specific to consolidation and not retrieval. We conclude that caffeine enhanced consolidation of long-term memories in humans.”
peakmemory 
Another reason for me to continue enjoying my espressos!