Don't have time for those at the moment. Here's a post I found to explain what I mean.
Well first we have the famous Frieza planet busting feat Here
Many people think that Frieza was serious in this attempt, and that even with all of his supposed strength he was only able to trigger an explosion with a 5 minute wait time.
But here we see that Frieza (at 50% strength mind you) intentionally used just enough power to cause an explosion that would carry a 5 minute delay all just to fight Goku at full strength.
That was just an example of how the story of Dragonball Z is told through the characters in lieu of a narrator. Characters can rarely outright lie in this format because the reader can't be misinformed else the story loses it's ability to speak.
A character that is a known arrogant idiot is Mr. Satan/Hercule. Hercule gives a lot of misinformation throughout his time in the series, but every time he gets corrected directly or indirectly by someone who knows the truth.
Here we have Hercule boasting about how he is undefeatable, then not even a page away he's corrected by Krillin.
Again we have Hercule bragging about being able to beat up Kid Buu. Immediately after we have Goku looking confused about Hercule's statement questioning it's validity. Hercule then clarifies that he is lying but only because the people wouldn't listen otherwise.
Next we have Hercule fighting Trunks in the World Tournament, being completely outmatched in strength as we see here.
On the next page we see Hercule take the punch and all the damage seemingly scot-free, fooling even Trunks.
If it had ended there the reader would be confused to whether or not Hercule really was strong, but the last panel lets us know that he was just putting on a show.
Next we have Hercule claiming that Kid Buu is under stress simply because of his ki. Imgur Even Goku is startled by this wondering whether or not it's true.
But later we see Kid Buu spit up Fat Buu and then are told that Hercule's ki wasn't the reason and that it was Fat Buu's presence inside Kid Buu that caused Kid Buu's inner turmoil when faced with fighting Hercule.
Moving on now, we have Goku fighting Uub (the reincarnation of Kid Buu as a human). After the fight Goku claims that he wants to train Uub to be the protector of the Earth one day.
But again here in the final panels we have Piccolo and Vegeta hinting at Goku's "true" purpose, with Goku revealing at the end that he really only wanted to train Uub so they could have a good fight one day.
I don't want to read the entire story over again just to find more examples, but I think what I have here should suffice.