Ask HN: Did you ever resign from a company on your first day?

I have had an offer from a company in Berlin, Germany around two months ago which I accepted and have had to join next month. I have got a better (much better in terms of salary, relocation benefits, tech stack etc) offer from another company in the same city and I want to accept that. Now a part of me is telling me that I should stick to what I accepted before and it would be wrong if I tell them that I am not coming and the other part of me is telling me that I will not be happy there both from the work that I will be doing and the other monetary benefits and so wants me to accept the second offer.

I am confused now that whether I should join them or accept the other offer. Did you ever had a situation like this, did you ever resign from a company on your first day?