Thank you all for the responses!!!! I really wasn't expecting so much advice - I really appreciate it. And, apologies - I would reply to everyone individually but I think there are too many responses for that to be feasible - I really wasn't expecting so many responses. Thank you all again!
I guess the main takeaways then are (i) Corporate travel may be over-hyped (ii) Pursue only careers which truly intrest me and which I'd truly enjoy (I was largely planning this - travel &hope of GGL would just be a nice perk and may have swayed me in a direction if I was undecided) (iii) Having (a lot of) money and holidays => Lots of quality high-end leisure travel which is enjoyable > lots of forced business travel which is not enjoyable (at least after a while) (iv) Have fun at university and pursue academic interests and don't be overly career oriented (although a bit of that is okay) (v) Flying less in J/F at a young age may be better in the long term to help me appreciate the luxury that it is when I'm older and to ensure that my pleasure of flying does not go with time (vi) Friendship/ Family/ relationships, at some point, become more important than flying (vii) If I do want to fly a lot in J/F, then IB/ Law/ MBB consulting or similar such industries are where to look. If I chose to pursue a career as a development Economist or similar, there'd be less of that to look forward to (although, correct me if I'm wrong, but World Bank has strictly J+ policy for long-haul, right?).
Thank you all again for your insights & advice - maybe I'll be back in a few years with GGL under "Program Affiliations" posting all the latest about BA & BAEC on these threads!