Do we really have to go over this every once in a while? This theory of lost bitcoins is different every year and varies depending on the analytics firm. Some claim that 3m is lost, others that 5m, and there are even higher estimates.

The deal is, they treat coins that haven't moved for a few years as lost. Some companies take 5 years, but it's different for others, which is why the estimates differ so much. I have coins that haven't moved for over 5 years, so to these people I own lost coins, but I can use them at any moment. If someone offered me $150k right now, I could trade them a few BTC from 2017

How much can you own? It all depends on how much you're willing to pay. That's it. If you pay above market price, you can easily get 100k BTC because that's daily volume of some exchanges.
What's the most any single person can own? Again depends on how much you're willing to pay, but with enough funds you could probably get to 1m. Then people would start to wonder why you're collecting so much and stop selling, or begin to offer much higher prices, so you could maybe get to 1m before you drained the exchange volume too much for real offers to stop appearing.

What does it mean? You'd buy out all the day traders and pump the price so much that they'd be unable to buy back. You'd eliminate them from the market completely.
Large players would try to crash the price, thinking you're overextended, but if you had enough money, being able to print like the government, you'd stop that and buy out all their dumps.
You'd set up a buy wall at above market price that would eat up all small traders.
In the end you'd dictate the price by setting up buys at certain levels. You making an order at $500k would make the price ticker go to $500k, and doing so at $550k would make the ticket show 550. That's what happens when you have a ton of money and decide to buy something. The price is what you want it to be, as long as it's above the starting market price.
That doesn't mean you'd be able to buy all the bitcoin in circulation. That would never happen! You'd maybe be able to buy a million before scaring the market. And yes, you can scare the market by buying too.

We want as many Bitcoins as we can.  Maybe that will not easy to have but we have time to accumulate although the price increase more than $100k. Our target will be long term so we want to achieve our goals in the future by having many Bitcoins.

We don't know how high Bitcoin will be in the future, let's say 10-20 years from now. But if we have many Bitcoins that we prepare from now, we will be one of richest people in our city. We can change our life better than now and prepare our kids to enjoy life.

We can also give Bitcoin as legacy to our family and split the amount to each person. Many things we can do with our Bitcoin in the future so we should work smart from now on.