Is your memory shot like mine?

I used to be able to read or do problems of 1 chapter and remember all the key definitions or ideas (e.g. axioms of a group, chain rule, etc) and never have to look at it again. Now I wake up the day after reading, go back, and can't remember shit I did yesterday.

Technically it isn't a problem because I can roughly remember 'that theorem I read a bit ago might help' when doing problems - but how do I fix my fucked up brain.

Is it using technology too much?