Calculations in bed?

I received Harris and Bertoluccis textbook on Symmetry and Spectroscopy today and I felt slightly hit by the dedication: «I dedicate this book to the student who is willing to take it to bed with him at night, along with a pencil and occasionally a calculator, and who falls asleep with a smile on his face». Of course I was reading that in bed… I also think I felt asleep with a smile on my face. But a calculator in bed..? That sounds like an idea from an engineer :) Truly, math can be rather fun, but «chemistry without numbers is poetry» (Andrew Shaws). And I would rather read poetry than do calculations in bed.