No one has said that folk can't change their mind, but they may get exasperated by those who use that to say we need to hold referendums until the result they wanted wins. Change you mind after we have been out of the EU as long as we have experienced being in and you can make a sensible decision rather than moan at the previous result and wish to overturn the majority decision.
Clearly the attempt to compare against a general election fails immediately as the new government is in power for the allotted time before there is a re-vote.
I've no idea if majority opinion has swayed due to fear stories towards not being a nation worth the title and remaining ruled by the EU elite, but in the event that it has, shame on those pushing the fear scenarios and it would be a destruction of common sense and the worst for our nation.
The UK has a reputation for being stronger than that, not giving up what they know to be right to avoid the necessary change period. I trust this present generation will prove equally resilient and worthy as the previous ones.