step on the same rake

step on the same rake - наступить на те же грабли

I consider this allegation a crucial mistake as we step on the same rake... - Я считаю это заявление серьезнейшей ошибкой, поскольку мы наступаем на те же грабли...


to walk into the same trap

to walk into the same trap twice
The straight answer to this question is: 'to make the same mistake twice'. Whether you use the version of it suggested above, or choose this one depends on considerations of style and register.

Just to make it perfectly clear, this sentence refers to a rake of this type, and it is a cliché in comedy to have somebody walking along, not looking at the ground, and step on the head of the rake (which is lying with the tines pointed upward). This causes the rake handle to rise up and smack the walker in the face. It's funny in a slapstick sort of way, and everyone has seen this gag. That's why the meaning is obvious even though we've never heard this expression. It is telling the person not to make the same stupid error twice, and instead to learn from his mistakes.

do something once too often
to cause trouble for yourself by repeating dangerous, stupid, or annoying behaviour
once too often
used to say that someone has done something wrong or stupid again, and this time they will suffer because of it
You've tried that trick once too often.

You poked me once too often = you poked me many times before, but that one last time you poked me was really painful.
It means he poked one time too many. Say that the 10th poke was the one that hurt. If he had only poked 9 times the patient would not have felt any pain. But he poked one more time and the patient felt pain. Thus, the dentist poked one time too many to avoid pain, or once too often.
"Once" means "one time" here (one poke). One poke more. The dentist, we presume, poked the tooth at least one time, but probably twice or three times, and the man could bear that. But the dentist then poked it again, and that one time again was too much for the man.

"Once too often" can have a slightly different meaning.

Instead of that one additional time causing a higher level of pain, it could be that the one additional time exceeded your patience.
For example:
A child whines to his mother that she wants ice cream. The mother says "no".
The child whines again. The mother says, "no, it is too close to dinner time".
The child whines again and the mother says you are "trying my patience".
The child whines again and the mother says you "whined once too often" and proceeds to spank the child.
It is the same whining, it is just that the mother ran out of tolerance for it.
So it could be that the patient was hurt each time the doctor poked, but that last time he no longer felt obliged not to complain.

once too often
слишком часто
No sudden catastrophe had overwhelmed them, no grand conflict in which they could at least die nobly. They had simply got drunk once too often and lost their money... (R. Aldington, ‘Soft Answers’, ‘Now Lies She There’) — Никакая внезапная катастрофа над ними не разразилась, не участвовали они и ни в каком социальном потрясении, благородно рискуя жизнью. Они просто слишком часто прикладывались к бутылке и в конце концов остались без цента...

do something once too often
do something once too often phrase
to cause trouble for yourself by repeating dangerous, stupid, or annoying behaviour
He’s insulted me once too often. He’s going to regret this!
Thesaurus: to cause problems for yourselfsynonym
Main entry: once
Useful english dictionary. 2012.
a tool for making soil level and removing leaves from the ground, consisting of a long handle with sharp separated points on one end that the soil etc is caught in