Karmanye Vadhikaraste - This is what Lord Krishna meant.

कर्मण्येवाधिकारस्ते मा फलेषु कदाचन |
मा कर्मफलहेतुर्भूर्मा ते सङ्गोऽस्त्वकर्मणि || 47 ||

karmaṇy-evādhikāras te mā phaleṣhu kadāchana
mā karma-phala-hetur bhūr mā te saṅgo ’stvakarmaṇi

"Understand, 'Do your duty, don’t expect the results' is not told from that context, that if you work for ten thousand rupee, you may get only ten rupee but console yourself, don't rebel, don't feel injustice is done to you. No! Fool. Life is such if you work for ten rupee, you will be showered with ten billion rupee. But if you think you are going to be getting ten billion rupee and you need to work for that, you will be overwhelmed and never start the work! Listen! ...Results are caused by the cognitive shift, not by the work!

This is what exactly Krishna means - work, don't think about the result because result will be huge, and if you are thinking about the result you will do the reverse calculation - how much of effort you need to put for causing the result. Then you’ll get overwhelmed about the effort you need to put and you’ll never start.

There are two states - Ishvara and U-shvara. Ishvara is taking responsibility and making it happen. U-shvara is getting overwhelmed about the actions you need to perform for the result you need to cause and never move anything. And if you are forced to move, take u-turn!"