For me it's a hobby, because I would like to travel to other countrieswhere I can try to use what I have learnt.

If it has made me smarter, I haven't noticed it;  but it has made me more aware of my cognitive weaknesses, and that might, in a perverse way, be called smart.

For me it is a hobby, I just like learning languages. 

the more languages I know, the better I can understand another people and their culture.

so, for me it's like an amazing trip to another world)

I learning other languages for connecting with two different things.

Maybe the people have different nationalities or share different cultures, thinkings, lifes and information. It really makes me feel excited!

And following grown ages, I'd like to use language skills to get a better job, but it’s just  my own slight thinking, because I don't know how to start it!

I don't know learning languages whether could help you be smarter or not.

But I'm sure that your mother tongue will be better then you were, especially you are doing language exchange! :)

Learning languages is one of my hobbies, but it also can help me a lot in my work!