as i just finished my REU and was on my way to take my flight back home. one of the students offered to give me a ride to the bus stop so that i can take the bus to the airport, which is about an hour away from school. this is where the main problem occurred: there were 2 bus stops near the school, one about 5 min away from school, the other about 15 min away. i got the directions about the bus stop w/o realizing it was the 15 min one, when i thought it was the 5 min one. thus, the guy who was giving me a ride thought 30 min before the bus coming was plenty of time for him to give a ride to another student who needed to go to the post office, which was about 5 min away. this student was willing to walk there, but he offered and gave her a ride anyway. the guy then came back about 15 min before the bus arrived and picked me up and gave me a ride to the bus stop. it turned out that i arrived about 30 seconds too late! the bus driver was an ******* and didnt let me on board because i didnt have my bus ticket which i would have bought there, which would have taken like 5 - 30 seconds to buy! this was the worst part: most of the students who lived in our dorm had already left. since no more buses left for the airport in time for my flight, i had no choice but to have this same student drive me all the way to the airport, which was in the opposite direction of where he needed to drive home. or to ask one of the profesors to give me a ride. so i asked if my prof whom i did research with could give me a ride there, which he agreed. i explained the whole thing to him honestly, and i even blamed myself to him, saying that i should have known that it would take 15 min, not 5 min, to get to the bus stop on the way of driving me there, though he didnt appear angry, he certainly didnt appear too happy. usually he smiles every now and then whenever we have conversation. this time, he never smiled. i'm very worried that i appeared very irresponsible and impolite to him and thus really screwed up earning a good letter of rec from him did I?