Doing daily or complex activities without attachment

Is it truly possible

I'm not sure what "truly" possible means: can anything be, "possible, but not 'truly' possible"? Perhaps the question is a bit extremist: perhaps you're asking about something beyond what's 'truly' possible.

to do activities without expectations

Your question reminds me of the saying that "dharma is good in the beginning, good in the middle, good in the end" ... I think that maybe "doing activities without expectations or some aspect of the self ideal attached to them" might be sensible, and better than the alternative, even "in the beginning".

There is some ambiguity in the question: i.e. "desire", "attachment", and "expectation" are similar and sometimes used interchangeably. Nevertheless, asking whether it's possible to "do activities without expectations" reminds me of the question of whether it's possible to go to the park without desire.

Brahmana Sutta

Didn't you first have desire, thinking, 'I'll go to the park,' and then when you reached the park, wasn't that particular desire allayed?

Similarly, when I do an activity then I probably have an expectation, and I do it because I have expectations, for example, "If I walk down this path, then I expect I will arrive at the park."

But expectation can be disappointing, for example, "If I'm nice to him then I expect that he'll be nice to me"; so at that point (if an expected result doesn't materialize) it might be better to not have expectation (too much expectation, or misplaced expectation).

In summary maybe it's sensible to have some expectation but not to be attached to it: "if I prescribe him this medicine then I expect his disease will get better ... but, if the symptoms don't get better then I'll change (not be too attached to) my expectation and then I'll come up with a different plan of action."

Still it is easy (perhaps too easy) to develop attachments and to accept those attachments as a thirst.

or some aspect of the self ideal attached to them

I'm not sure about "the self ideal". Some of my ideas on that subject:

• There is no "self" -- when I'm working (writing software) for example then the software is being written but there's no particularly special me who's writing it, and/or that's not the same me as the me who does something else later. I think that's kind of the Buddhist "anatta" theory, the Buddhist view about "identity-view" (that there isn't a fixed/permanent identity to be found)
• Having self-ideal and feelings and expectations will restrict my actions -- for example I may crave the experience of being a good worker and therefore only do what I'm good at, and avoid opportunities to try new activities that I'm not already very experienced at
• There are degrees of more and less "self-ideal" (which gets back to your question of what's 'truly' possible) ... see for example the answers to this question, How are 'conceit' and 'identity-view' not the same?

Maybe this is another question, but did the more complicated concepts and practice techniques Gautama described attach to the context of that day and age?

The answer is clearly "yes", and a follow-on question is whether it also attaches to our day and age.

There are even many people in different situations in our day and age, and so a good question is what practice techniques can we apply to ourselves in particular.

So part of our job is to hear Dharma and to understand Sat-Dharma.

And maybe they are only best suited for monks? (Maybe we shouldn't take them to the workplace or family.)

Maybe that's a black-and-white, all-or-nothing, extremist view.

I suspect it's true that monks may become monks in order to be (i.e. expecting to become) relatively free to practice all the time.

I suspect it's helpful for laypeople too to take these practices into their lives sometimes, even if they also have other things to do and think about, and are not practising full-time.

In Buddhism things are slightly different. Being aware and mindful of what you do (as you say) is more of a hindu concept if it is from the Bhagavad Gita.

This itself is good. A surgeon, ballerina, acrobat, etc. will need to be mindful and aware. If they do not then they cannot do their job. This will make you do a good job in whatever you do.

In Buddhism what need to be done is you should be aware of the arising and passing away of sensation you experience with equanimity. (Pahāna Sutta, Avijja Pahana Sutta 2) This is what will eradicate the 3 evil roots which in turn helps you realise nirvana.