The 3rd GOLDEN RULE: 

do not talk to your boss if you are 

1) tired, 

2) under caffeine effect, 

3) pissed by boss, 

4) drunk.

speed

Boss: - How is your writing? Is it fast enough?
Me: - You should know better then me, it is never fast enough...

Miracle

Sometimes it seems that all work in molecular biology lab is attempt to produce a miracle*... and then you need to make the miracle reproducible**.


* You work hard, try everything and sometimes result (surprisingly) is successful and it is a MIRACLE
** better also publishable

- are you tired?
- no, I am over this point!

Golden rules

GOLDEN RULE NR 1:
Never ever wonder "if your boss is that busy, what is he doing" exactly the same moment he will appear with new task for you!

GOLDEN RULE NR 2:
Never ever ask your boss what to do 30 minutes before you want to leave the lab!

Worse case scenario

... you are entering the institute (9.15 AM versus usual 8.15 AM) with fellow PhD student... holding coffee from the automate... relaxingly chatting...

It can't be worse in this moment
... meeting the boss in gloves coming out from the lab (surprise - he was the 1st in the lab)... complaining that he can't find D2O and that we have mess in the fridge (he haven't seen it one week before :))...

...to complete the picture...
...we both said "shit" out loudly when we've seen him coming...