Clear understanding, no (not sure anyone does). But I'll give an opinion, from the point of view of someone who isn't a Leaver or Remainer. For the current mess itself, I'd say the blame mostly lies in three places.
1) Cameron & Friends. Used the promise of a referendum they didn't want as a bribe to win an election. Then, delivered a useless fudge of a 'renegotiation' that addressed and changed nothing, largely because they went into said discussions having already said they wanted to stay regardless. Then called and ran the referendum with the naive view that because they didn't expect Leave to win, they could just ignore the possibility and do nothing in preparation, setting the scene for a rushed mess.
2) Persistent Remain Camp. Essentially, the Man Utd fans being told to cheer for Liverpool. Not the general public, but the people in highly influential positions (government, civil service, media) who haven't stopped working to either stop or heavily soften Brexit since the vote happened. Massively undermined any position Britain took and significantly weakened any hand the negotiating team had.
3) May & Friends. Triggered Article 50 too quickly. Then put together the 'negotiating team' (some of whom are members of 2) above) who, as far as I'm able to tell, have achieved the impossible in that they have Leavers and Remainers agreeing with each other on something Brexit-related... sadly, the thing they're in agreement about is that the deal is crap.
Limited it to three because my Brexit-fatigue is currently close to an all-time high.