It is for that reason that I think everyone should spend a while writing in assembly language. I spent some time doing graphics demo coding for fun, and it has given me a deep insight into the inner workings. Of course, you're not going to do much work in assembler, but you get a fine feel for efficiency.
Even though you're miles above that level when writing Perl, it gives you a sense for what approaches generally are efficient, so even when you're not trying to squeeze cycles out of your code (and most of the time you shouldn't, you should be coding for maintainability), you are instinctively economical. It simply sharpens one's senses.
Makeshifts last the longest.