Descartes is often stuck in his internal "bubble" because of the nature of his meditations. Being meditative is an inward practice, and does not allow for getting out of one's bubble very easily. A person's search for certainty can certainly backfire, especially if he or she spends too much time in that internal world. It is important to understand and see the world for what it really is, instead of what one wants it to be or hopes it will become. It is vital to step outside that bubble and see what is real in the world, so a person seeking certainty can base that certainty on truth and not on what he or she just wants to be true.