What is a good excuse for not picking someone up?

How old were they, and did they make it back safely? Why can’t you just say you forgot instead of making up a lie?

You could tell them that you really had to chop some firewood.
That is what my parents did when they did not show up to my graduation ceremony.

Tell the truth and take your licks. Your lies will find you out.

Say you were abducted my aliens.

Gotta include some zombies in the tale.

Abducted by alien zombies.

You took them literally and realized that, in your current shape, they are far too heavy to “pick up” — so you’re off to the gym.

Just tell the truth. You weren’t ready for that kind of responsibility. You’ll let them know when you are.

Best thing to do is the truth. I agree with @Dutchess_III

When you step up and tell the truth, it can be so embarrassing and shameful that you never want to feel that way again, so in the future you do things to avoid feeling that way again. That’s where you learn to be responsible and dependable.
However, if you make up stories to cover yourself, you never learn to be responsible. Also, people can usually tell if a person is lying. They may never say anything, but they know. And they start avoiding them.

Im ashamed to tell you that I did in fact tell an untruth – I said I had gone away for the weekend I couldnt get back because something cropped up and my mobile phone battery had gone flat so there was no way of getting hold of them to let them know…...............I think I was believed! I’m not very proud of myself – just a tiny bit…..

Sorry honey. I wouldn’t be the tiniest bit proud of myself. Besides, trust me….they know you’re lying. They’re asking each other “Why didn’t she borrow someone’s phone?” Of course, if they ask, you can tell them you were filming a Hannibal Lecter movie and they had you tied up in a well for a shot and they forgot about you for 48 hours.

Just because people don’t confront you doesn’t mean they don’t know.

Dutchess III you seem a little uptight “honey” might I suggest you go and get yourself an orgasm but I’m guessing you may have to achieve that ALONE?? best wishes…..

Well, it depends. How old were the students you “forgot” to pick up? If they were adults, then yeah, no big deal. If they were first graders then it IS a big deal.