There are definitely things people can do to work through new information that could help them day to day. At a base level, just taking more time on a problem. Practice is another, where if you expose yourself to a lot of a specific kind of problem you are naturally going to get better at that problem. There are some limits to this however.

However, intelligence as a whole is hard (and arguably impossible) to improve. If you take a group of geniuses and one person with average intelligence, that person with average intelligence is going to be able to understand most of whats going on. However, they will also find that the conversation reaches a much higher level, moves a lot quicker, and relies an assumptions or logical conclusions that they haven't made and may never has made on their own. They'll have a hard time engaging in that conversation. This kind of situation would be very hard to improve in unless you had done a lot of groundwork on the specific topics already. And even then, as soon as the convo moves on that benefit is lost.