You should not have a personal mandate on how many stocks you hold. You will restrict what you can do.
Imagine you tell yourself to only hold 10 stocks. One day another stock suddenly become a great bargain what will you do? Liquidate an existing stock just to add this bargain? When that liquidated stock could be a bargain as well.
Instead, another way is you could add this great bargain too to your portfolio (if you have spare cash). Then have a plan after that to trim holdings maybe? Like if it run up 50% with no apparent reason can consider to sell and add more to your current holdings.
The thing is, don't be jealous about those people who all in on one stock and it become a multi-bagger. There are a lot of people who did the same but see their holdings get wiped out. Most are no longer on this forum also anyway since once you wipe out your money you are unlikely to continue investing anymore.
If you throw all your money into one stock but lose sleep then its not worth also. Definitely if you diversify more then your overall portfolio will only be at best growing slowly since if one stock suddenly run up your overall portfolio gets pulled back by the laggards. But at least its steady?
Always remember to DYODD....

Options, “Options” in English.
It is based on the principle of leverage to increase personal profit.
Simply put, it's small and big.
Options changes, English “Motivation Option Activity”.
A change in options refers to the occurrence of a large number of transactions in a short period of time, leading to a surge or collapse in options/stocks. Since options are different from stocks, all options transactions are published and displayed on the options chain. We judge the possible surge/decline of stocks by observing changes in the options chain.
Because most of the changes in options are bought by institutions, they have sufficient information, sufficient research, and strong capital to buy, so judging the rise and fall of stocks based on the direction of the changes in options will help to a certain extent.
Changes will occur within a very short period of time. By tracking/following changes in options, we are provided with a reference for the “surge/fall” of the stock market.