timestamp – Query about Bitcoin’s Median Time Previous

I used to be presently studying the e book Mastering Bitcoin written by Andreas and was fairly confused concerning the idea referred to as Median Time Previous. Hopefully I can get a few of your recommendation.

From my understanding, when creating a brand new block, its header time should fulfill two major situations:

1. It should be larger than the median time of the previous 11 blocks
2. The time offset between itself and community adjusted time should be lower than 2 hours.

That is what I perceive about situation #1, contemplating 11 blocks with their given header time :

#1 – created at time 1

#2 – created at time 2

…

#11 – created at time 11

When a block #12 is created, based mostly on above rule it’s attainable to set its header time to 7.

If this occurs frequently, is not it bizarre to have a block’s header time going up and down like that ?

Thanks.