I really can't see any one knowing too much , I'd opt for not knowing enough, no offence meant.
I do not hold with the saying 'ignorance is bliss' at all.
Nor do I find that 'knowing too much can make you miserable'.
I find when i am miserable i need to remove the veils of ignorance which fog and confuse, as smoke and mirrors are the actual causation of the unhappiness.
I have only found understanding and the lack of ignorance to be where i find peace, bliss and acceptance live.
I have found, it true for me anyway that....... 'The truth will set you free'.
I agree with socrates about a lot of things such as 'the only good is knowledge and the only evil ignorance'. And well, many more..... May I suggest, checking his works out if you haven't already.
Also...'The only true wisdom is knowing I know nothing' or 'The more I learn the less I know,' whichever.... Words to that effect.
To some this may seem a contradiction and I can hear the nay sayers with their, 'You can't have it both ways,' Boll*cks. Yet, I have found that you can....As it is not an either or situation...so little in life is.
Don't get stuck in the law of two. The thorns of truth will snag if you don't keep on making enquiry....Even upon the things we can be so sure and certain of. As there is always more to glean even of the things in life one feels are crystalline in their knowing......But, that's just me