Permanent exp multiplier

Ok the idea is this one: there could be certain rare objects or insect that you could get via using whatever your exp tree area you are using at the moment (for example: if I am minning there's a chance to get a rare stone that can give me a chance to permanently multiply my mining exp, or a rare bug that I could capture and use it to make a food to multiply exp for certain time. Or if I am fishing the same case: a rare drop to get a x2 exp for fishing. I think you got the idea) because experience is the most important mechanic but the problem is: you barely get experience to upgrade your character so this could be a solution for this lack of experience problem :D.