A second stage in the evolution of the Linux user comes when the individual gains some measure of trust in his decision to switch. At this point, the user has learnt that there is indeed some merit in having moved to FOSS and does not need to justify his existence to himself every waking hour. There is only the rare need to secretly use Windows to do things which he cannot figure out to do under Linux.
At this point, the Linux user stops being overly defensive and abrasive. He stops shouting loudly on forums about the virtues of Linux - but he shifts into a mode which is more persuasive and tries to convert everyone he encounters into a Linux user. At this stage of evolution, the Linux user can be a pest. You often encounter these people at trade shows, Linux installfests and the like, do-gooders who are always trying to get people to switch from Windows.
This user is acutely conscious that Linux is a fringe operating system. This makes him even more determined to "improve" its status and all his evangelising is geared in this direction. He is defensive when questioned about Linux, but not shrill like the stage one user. He has several arguments of substance to rebut common myths about Linux.
However, this does not mean that the user who has reached this stage is not going to go back to Windows. Several do go back, due to one reason or the other. In most cases, it is because they are not really enjoying the experience and have moved to the second stage because of peer pressure.
They may be part of a Linux user group and do not wish to be seen as n00bs for too long. They may work for a company that uses Linux on the desktop and may not want to stand out as oddballs. But the strain finally becomes too much and back they go to the world of Windows.
As with the first stage, many never go beyond the second. Indeed, some are very happy to remain as do-gooders, often interfering with their friends' choice of operating system, then apologising and backing away. This is the stage when the Linux user feels he is doing the world a load of good, persuading misguided people to follow the straight and narrow path.
The second stage Linux user often realises that going to the next stage will take some application and hard work. He may not be willing to put in the effort. Else he may lack the intellectual ability to do so. The latter type often ends up as a "free software advocate."