Each human being is different, because each being lived a different life, experienced many different situations, people and environments, as such each damage within a human being is also different. Therefore, depending on how damaged one might be, how open is ones mind to meditation and its effects, how much information one has experienced and how willing is the mind to accept new information and realities, all will have an effect on how deep and how long each connection will take for each human being.
Therefore, if you are an opened minded person, who is highly educated and well travelled, and if you had been working for a while to connect your first three multidimensional layers, such a person will be more likely to connected on a very deep level (or connect to the forth layer/higher self/wisdom body) much easier and quicker then those who had just started their journey on such a road. Like always and like anything and everything in life, it depends on the individual and how dedicate they are to their end goal.
A strong determined character that is intensely focused normally achieves the goal much quicker, but no one and nothing can place a time on such an event, nothing is per chance because everything occurs at exactly the time and place it is meant to be.