To add to that, the core of his strategy is to invest in "high quality" companies, at a reasonable price.
He defines high quality specifically in a value of ROCE (Return On Capital Employed), which is (almost) net profits divided by total assets. This shows the return the company is generating on capital employed (not taking into account long term debt) - i.e. how valuable will the company become if it is not saddled with any debt.
He chooses companies with ROCE around 25% or higher. Assuming a company reinvests its profits internally, then he argues that its intrinsic value also increases by 25% each year.
Two points he does not answer in his presentations that I have seen, are the effect of debt servicing on this process, and why doesn't the efficient market theory discount this effect (by making the shares correspondingly expensive at the outset). The implicit answers to these two questions are that compounding by 25% per year will deal with the debt problem over the longer term, and that other investors don't understand the long term uplift of this kind of compounding, leading them to value the business in aggregate higher than, but not sufficiently higher enough, than other businesses with a lower ROCE.
Edit: Just to say that in the video of the 2020 meeting posted tonight, he explains this strategy at time 16:48
I've been looking into this tonight.
Watching the two annual shareholder meetings for FEET (Fundsmith Emerging Equities Trust), for 2017 and 2019, he says that the fund underperformance of net asset value was caused by outflows of money from far east actively managed funds, into far east index funds (ETFs), resulting from general investor sentiment in favour of passive investing, and regional investing. He says that the sectors of the companies he is invested in are under-represented in the main indexes, hence demand for his companies dropped in aggregate, along with the price). It sounds plausible, but might be an excuse of course.
time: 50:50
time: 20:00
I think the key is to only invest in companies where you are fairly certain that the returns on capital are not going to trend down to the mean and the revenues will keep growing.
That is the only way this works.