I have this thought.. of whatever you might give isn't the same if someone would give it back (the same thing to you)...

Something made it even more complicated is the following :
lets say two people (lets name them A and B) went to buy a watch that costs 10$ ... A payed 5$ and B payed 5$ (cool till now)... then it turned out that the watch costs 7$... so the seller went back to A & B to return the 3$... but he kept 1$ to him and gave them 1$ each (two dollars, one for each person)..

now... both payed (together) 8$... and the seller has 1$...
8+1 = 9$... but the watch is originally 10$... there is a dollar missing..where is it ? no one I think can answer... so this might be lame but meh, this might also mean not whatever you can give is like whatever you can take (same thing).

That confused the living hell out of me... Im so confused

This is old! I know it. A hint, check what is half.

easy both of them paid 10 you can take out 7 which will remain 3 he gave them 2 and keep 1 which mean there is still 1 and it's the one that he have taken.....you can say 10 -2= 8 that they paid -1 =7 the one the shopkeeper took which mean they paid the whole thing and remaining for them 1.... or you can say they paid 8 cause the keeper took 1 for him which will remain 2 that he gave them....i don't see what is the problem with that ,hope i'm not wrong :)

is this a riddle/puzzle or a topic to be discussed !? :os :p

lol! this is a trick...you just talked until we forgot the beginning.
The seller received 10 pounds, gave back two (one each), which means now he has 8 (because he kept 1 pound for himself) and A and B each have 1!!!