Is it wrong to begin this sentence with on hindsight:
On hindsight, I sense I would not be what I am today if I had the same maturity and wisdom what I have now, twenty five years ago?
English Language Learners Stack Exchange is a question and answer site for speakers of other languages learning English. It only takes a minute to sign up.Sign up to join this community
It's fine to begin a sentence with an adverbial phrase.
Note that the most common preposition used with hindsight is in, not on. Here is an NGram showing the difference in usage. Here is an example that shows the use of the adverbial phrase at the beginning of the sentence, with the preposition in.
In hindsight, it would have been better to wait
As for the rest of the sentence:
sense: an ability to understand, recognize, value, or react to something, especially any of the five physical abilities to see, hear, smell, taste, and feel
think: to believe something or have an opinion or idea
same is normally used together with as rather than what.
In hindsight, I think that I would not be what I am today if I had the same maturity and wisdom as I have now, twenty five years ago.