It's not dissimilar to the general order-of-magnitude of speeds associated with various computer components (RAM, CPU, Cache, HD seek, network latency, etc.). But there are many more components in a biological system, and their interactions up and down the physical scales are sometimes not obvious.
A simple example of intuition: once you've sequence your DNA, how would you go about changing it? Which DNA? Is the 'sequence' you got back an average sequence across just those cells that were sampled? Is the DNA you would want to change both copies, in each cell, in every tissue?
Another example is running through how a PCR reaction works. The actual result of the process often trips people up the first time because it's not immediately clear that there is an infinite pool of each component in the system to permit self-reactions in later steps of the process. Once a component is used in the first part of the process, it's still there in later parts of the process.