I apologize for the previous joking response. I admire anyone who takes on a second language. I'm still learning French, and wow do I suck at it.

Anyways, you wanted to know how to say what you said in better English. Try this:

"My couple of eurocents: I recognize that difficult lessons become easier for me to undertake after allowing them to percolate in my mind for a few days"

Note that we both used graphic language specific slang phrases. You said "biting/melting in my brains" (which I just love and makes me laugh), while I used "percolate in my mind", which you may find to be just as funny when translated into your language. "Percolate" is a verb that means to slowly mix and then pass through a filter (like coffee dripping through a paper filter when it's brewed).

Or, you could leave out the slang and say:

"I recognize that difficult lessons become easeir for me to undertake after contemplating them for a few days".

But that's not as graphic, and therefore not as interesting.

Hope that helps. Again, I apologize if I offended you in any way with my previous response. 

Sascha