Should I be upset or was I thoughtless?

Yes she did do something wrong, OP knew full well that her friend wasn’t retiring yet gave her a retirement card anyway.

Yes I think you were being ageist. Women in older middle age are often overlooked or assumed to be incapable And then you persisted in the thoughtless “joke” by mentioning a bus pass. No wonder she was annoyed

You just wait until you’re 60-something and people write you off as you did your colleague.

She didn’t, she told OP it was the thought that counts and was overly nice to her for the rest of the evening, so if anything it’s OP who is looking to be offended.

I can see why that was hurtful to her given she had made it so clear she planned to do a course and then return to work and wasn’t retiring.

You knowing that and choosing to give her a card that specifically said retirement may have felt like you were indicating (however unconsciously) a belief that she wouldn’t or couldn’t follow through on her stated plans and would just end up never going back to work. She’s probably gotten a fair amount of people doubting her either openly or through condescension and subtext so she’s likely to be sensitive to it.

It sounds like an apology was due, but her behavior after was to show you she accepted you didn’t mean it that way and you can both move on.

So why did you get her a retirement card?

this.
But people are 'allowed' to get offended over anything nowadays. It's pathetic.

You made a bit of an error / faux pas but what you did wasn’t that outrageous.

Her response and that of the person who chimed in sound utterly graceless and rude.

You didn’t do it on purpose, there’s not need for them to make such a song and dance.

Except she clearly said she was not retiring!

A generic ‘best wishes’ card would probably have been better, but I don’t see it as a big deal.

Oh for goodness sake despite what everyone is saying you did absolutely nothing wrong - it was a lovely gesture and if she was a bit prickly about it then that's her problem. If course she was retiring and starting again in a new direction. She's 66 not 26 and you sound like a lovely person x

She was leaving work and was of a retirement kind of age. Not a big deal, don’t beat yourself up.

I'm sorry but I think the bus pass comment was putting the boot in.

would you give someone in their 30s moving to a new job a 'congratulations on your baby' card just because they are 'maternity leave' age?

this woman isn't doing qualifications 'just to keep her brain working' she DOES INTEND on working after said qualifications and had made this clear to OP, who made it clear to anyone who bothered to properly read her post.

ageist, sexist, classist, AND unimaginative, bingo!

Who says she's going to be employed in a new career? Perhaps she's going back to the same sector. Perhaps she plans on starting her own business. Perhaps she doesn't plan on having a "career" but still intends on /needs to work. Even if she does a degree then moves to working a few days a week on the tills in Aldi she ISN'T RETIRED.

The main thing is that the "silly woman" gets to decide herself whether she's retiring or not, not OP, and not you, a random and rather unpleasant, internet stranger.

This group of ladies sounds a bit snarky

You made an error. She calmly pointed it out and then was nice to you to show no hard feelings.
I think pp with the "happy holiday card for mat leave" sums up the nature of the error well.

How do you know? Maybe she’s training to be a counsellor, garden designer, bookkeeper? Anything really, especially if you’re self-employed.

Oops, oh, yes.

But this lady had specifically said she intended to go back to work?

The OP says she was leaving to do a course then continuing to work. We don’t know it’s in a completely new field- she could just be carrying on in her existing field (or a very closely related one) but with an additional qualification/ new employer. Ironically she might be even more employable after the course.

All of those people have been working in their careers for a long time, except yvette Cooper and she's not old enough to use in your examples.
The point is once the lady has qualified she will be too old to start a new career.

But she is retiring age. You can still do qualifications and not intend to find a job in that field just to keep your brain working.
I don't think op deliberately did anything wrong and recipient was gracious about it so best just to get over it all round.
I'm 67 so the last job I left i actually was retiring.

Charles became monarch sat the age of 73. Donald T rump is 79.

Good grief! Isn’t that exactly what she is doing? And, prey tell, at what age does anyone become completely unemployable?

You do realise that Ursula von Der Lyon is 66, Yvette Cooper (Home Sec) is 56 and looks to be going strong, Angela Merkel is now 71 and was German chancellor until 4 years ago. Lady Arden (former judge) was a Justice of the Supreme Court well into her 70s and there are 1000s of people, well into their 60s who are leading figures in law, medicine, business etc. Your attitude stinks.

Leaving or retirement are 2 different things
Do you really hate yourself OP or are are just a bit embarrassed