The first 30 minutes are going to be hard. This is the time where you will want to avoid the silence, boredom and discomfort of not doing anything by distracting yourself.

If you can sit with it for longer than that, you will eventually go inward.

Now, after about 30 minutes of going inward, you will notice that you exhausted that topic for the day. Your mind will begin to wander and you will cycle back to trying to avoid the boredom. Thinking you already achieved a lot, your mind will be even stronger in its attempts to distract itself.

If you can resist that for another 30 minutes you will go even deeper than before.

Essentially meaning that the 2 hours gives you a deeper level.