When you are an adult, you don't take trips. No, you go on an excursion or a vacation. You attend a reunion or a retreat. No longer a simple one syllable trip, no more riding in the back seat playing car bingo and dozing on your pillow while your parents drive you to a series of predetermined destinations: grandma's house and camp sites and hotels in small towns. No longer do you get to spend all your money (provided to you by your parents) at souvenier shops along the road.
When you are an adult, you buy plane tickets and rent cars (which means of course you must carry proof of insurance and proper identification). You must budget for food and hotels and incidentals. You must spend hours on the instant messenger and email engaging in multilateral travel arrangement negotiations with your friends; hashing out the details of when and to which airport you will fly and at which hotel you will stay. And there will be emails. Emails upon emails. Hitting "reply all" will become second nature as you discuss which sites you will see and when, as you makes lists of things to do and places to see.
That is, if you are me, and you have my friends. Lovely people, wonderful, intelligent people. But also people who need to discuss the details without ever stating their opions clearly, obliquely letting their preferences be known with subtle comments or perhaps with not so subtle ranting and pointless blog entries. If you are me you find that vacations are called such because they vacate the contents of your wallet, and you come home more exhausted then when you left. But also, if you are me, you look forward to seeing your friends, and look forward to being reminded why you are friends with these people, and to uncovering some great material for future blog entries.