This is two separate issues. The first is being aware of how much you can actually manage. The second is having the capability to refuse requests.
For Issue 2, here’s a rule of thumb:
If you find yourself wishing they hadn’t asked you in the first place, you should probably say no.
That way you’ll be able to distinguish situations from when you actually think you should assist vs. when you feel obligated. (If you actually think you need to assist, you should. Don’t go the opposite direction of always saying no.) Also, this advice assumes you aren’t playing any signalling games.
I’d say it is a matter of noticing apprehension at the prospect of saying yes, and listening to it.
This is two separate issues. The first is being aware of how much you can actually manage. The second is having the capability to refuse requests.
For Issue 2, here’s a rule of thumb:
If you find yourself wishing they hadn’t asked you in the first place, you should probably say no.
That way you’ll be able to distinguish situations from when you actually think you should assist vs. when you feel obligated. (If you actually think you need to assist, you should. Don’t go the opposite direction of always saying no.) Also, this advice assumes you aren’t playing any signalling games.
I’d say it is a matter of noticing apprehension at the prospect of saying yes, and listening to it.