I'll add my $0.02 here...I'm in my mid twenties and traveled A LOT with my parents when I was younger...between the fact that they were expats living in Asia and my dad travels a ton for work, frequent flier miles were basically free for us. I'm incredibly thankful for it...the perspective it gave me growing up was amazing, and I really feel more like a "global citizen" than a citizen of any one country. DO IT!!!
Side note: being around airplanes so much as a very young child gave me a huge love for airplanes. By the time I was 8 I could identify a 747, 737, A319/20/21, etc. I was also listening to UA's Channel 9 constantly and learning how everything works. Fast forward 15 years and I have a master's degree in aerospace engineering and am employed as a pilot flying some pretty cool airplanes...I owe it all to those trips to Thailand and England we did when I was younger!