Hot on the edges, raw in the middle
Use the microwave at 100% to cook or reheat and you can end up with something that is hot on the edges or the outside, yet raw in the middle.
However, if you utilize the manual settings, like 60% power level with more time you will find that the food is more evenly cooked. Or better yet, consult the manual and use the correct settings for the food type and quantity.
In the software development processes, breathing time/thinking time is good.
100% full bore gets you done. However, when you have time to think about the system you may experience remorse. To extend the microwave analogy--perhaps, you have a nice shiny UI but rotten messy code under the hood. With an appropriate