Does that is where his atavism comes from make sense?

It is a loan translation of the German mitmachen.

Yes, 'you can' does make sense; you're simply saying 'able to [do something]'. A person might say, 'You can visit the library,'.

Dreams do not "mean" anything. They are random neuron firings at at time of the sleep cycle that happen to allow individuals to remember the patterns of neurons that fired just then.

'Here boy, here. I gotta nice choc drop for you'. & watch him wag his tail !

first of all we know about what is sense? sense mean you work on a topic or think on his work.sometime we live a easy or simple life because our sense work those.