I see occasional slowing and problems with most Internet services from time to time, though Gmail seems to mostly avoid these due to having so many servers and the infrastructure to reroute around bottlenecks. The nature of the Internet is such that sometimes the route between your computer and the server you are trying to reach can be quite elaborate. When tracing traffic it is not unusual to see that your route does a complete circumnavigation of the globe in order to reach something that would be only a few hundred miles away as the crow flies.
This article talks about that.