Nationalism..good? or bad?

To have a global mind is a compulsory prerequisite for joining internations
This term of global mind has got me wondering lately, of whether it will clash with our feelings of loyalty to a certain country where we feel we belong or in other words, our feelings of nationalism
assuming that it does clash will bring us to the main point of this thread and that is do we need nationalism? as someone who has been in many countries, are we allowed to feel a certain loyalty towards one of them or have we gone beyond that and have embraced such open-mindedness that we deem ourselves a global citizen?
one thing for sure about it is that one should never underestimate the impact of the choice that you make regarding this question, because it can in fact forever alter your personality and your career path and ultimately how successful you are in life.
par example: someone who feels a certain loyalty will feel protective of that country and its image. he will find that he cares about fate of his surrounding environment and will be more outspoken towards these issues because he wants to make positive changes to his environment. his experience in going against the current will develop his personality so much so that he doesnt fear going against the mainstream anymore and will be more independent-minded (could be bad as sometimes the job requires a team player ).
on the other hand it is also entirely possible for someone who dont experience such need for involvement and choose to play safe and live a more easygoing and peaceful life.ppl of this category will need to possess high tolerance and conflict-mediating skills and it is perfectly acceptable to be that way and feel the brotherhood with all mankind.
personally i think i have fallen victim with the propagandas of earlier eras and the doctrinations in school that i truly feel that i love my country Indonesia very much with all its shortcomings. i found that out about me not long ago as i heard an old patriotic song being played in an ad and find myself feeling warm and actually shuddered as they showed flashes after flashes of the flag and stuff lol it was really silly to think about it cause we are not exactly in midst of war or anything but hey its what i am right lol. anybody who are more of my camp should beware......of internations cancelling our membership lol.....and they better not or its war lol lol........