I'm a huge fan of Hamilton, I have been since day 1 when he joined F1. However, there are things the driver needs to be responsible for - track limits, practice start areas etc. all of which will be covered on the drivers brief and track walk. Hamilton needs to take responsibility for this one.
I understand the 2 penalties were because he did it twice on 2 separate occasions.
It won't affect the overall championship, but Hamilton has now lost 2 wins this season for 2 rule breaks. The Monza rule was difficult to see - I think the FIA needed to be clearer on that Pit Lane Closure. Wins are wins that count towards your records when you leave the sport and look back. Those 2 wins that got away would rile me.
Well I think he has taken responsibility even though he asked his race engineer and got an affirmative reply, but like you say he should know the rules. Thing is things like this happen from time to time, he will simply put it behind him and get on with it.... it's what allows him to come back next time and do a reset... hanging onto things that might have been is pointless. If I were him I'd still be riled by China 2007 or Malaysia 2016.