is One Million +.
About a million things can be "identified" in a human lifespan.
(Things important enough to be included in the brain's filing structure. True, there are millions of colors, galaxies, molecules, etc. but you're not going to get to them. We're talking here actual not potential.)
Let's see ... there are 60 minutes in an hour ... 24 hours per day ... 365 days ... 72 years ......... ahhh ... hmmm... At one new thing per minute you can consciously identify 37,843,200 things in a normal lifespan.
[Minus about 12 million for when you're sleeping ... minus another 10,000,000 for working at the same old job day after day after day ... minus another gadzillion for TV reruns ... You get the picture. The time you actually spend seeking (and more importantly ... finding) new data is much less than "every minute" of every day.]
That's why there is an operational game "Twenty Questions" in which you think of something and the other person has twenty yes/no questions to guess what you're thinking of.
is probably a fair estimate.
And, naturally, your best strategy is "division by halves" to get the answer fastest.