Lose (one's) grip on (someone or something) American British phrasal verb
1. To lose a firm grasp on someone or something with hand
Marry lost her grip on the horse and then fell into a pond nearby.
Hang in there! Just a more 2 inches you will reach the mountain top. Don't lose your grip on the rope.
2. To lose a clear understanding of something
He loses his grip on technical problem, so he makes everything messy.
I feel like losing my grip on this situation, I can not settle this tense argue.
The verb "lose" should be conjugated according to its tense.
If you fall for someone's trick the first time then they are at fault.
Are you going to mess with me again? Fool me once, shame on you; fool me twice, shame on me.