How to deal with a person who constantly explains things you already know well?

Question

One of my colleagues enjoys explaining things a lot, and he does it very well. This comes up handy when I am missing something on a subject: I come to him, and he teaches me everything I have to know about the thing.

However, this also has a negative side. Sometimes, he starts explaining something that I already know, and continues with the explanation no matter what. Telling him something like: “Yeah, thanks, I already know all that; can we please go back to the original question?” has either no effect, or he barely responds: “Of course, I remember the original question, just let me explain [the subject] first.”

Here's how a recent conversation sounded like:

Me: do you think it would be better to use this approach rather than the one we considered originally? I'm not sure if the new one is clear enough; it doesn't look particularly readable...

Colleague: the benefit of the new approach is that it cleverly uses the polymorphic behavior of the classes. You know what polymorphism is, right?

Me: of course I do, it's when...

Colleague: it's when multiple types share the same interface, which makes it possible to use those types in the same way, as soon as the use only needs the members which are declared within the interface. One of the interesting aspects of it is parametric polymorphism. This is what translates into...

Me: into templates in C++ and generics in Java. I know. Speaking about the old and the new approaches...

Colleague: exactly, templates and generics. They allow you to use...

Me: I know what generics are...

Colleague: ... an object independently of its type, as soon as it extends a specific interface [...]

Those discussions sometimes take a long time, and are not very useful: I would rather prefer focusing on things I don't know, or don't know well. However, all my attempts to refocus the person failed.

I want to avoid to be rude to this person at all costs for both personal reasons and because he has valuable knowledge to share (personally, I find myself already quite rude to interrupt him, although he doesn't seem to notice or may be used to it).

Therefore, what is a polite way to focus his attention to the matters which are important to me, away from subjects I already know well?

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Note: there is already a question here with a title looking a lot like mine. However, the specifics of the context of the other question and the reaction of the poster which was rather different than mine means that the answers don't apply much to my situation.

Answer 1

Me: do you think it would be better to use this approach rather than the one we considered originally? I'm not sure if the new one is clear enough; it doesn't look particularly readable...

Colleague: the benefit of the new approach is that it cleverly uses the polymorphic behavior of the classes. You know what polymorphism is, right?

Me: of course I do, it's when...

Colleague: it's w...

_{(emhpasis mine)}

An approach you could try is to not ellaborate on your answers.

This coworker asked you something that a yes/no answer should suffice; there was no need for you to try to explain yourself to this Colleague, you could have just answered "Yes" or "Yes I do".

By you engaging on trying to explain seems to encourage this person to continue with their very enthusiastic explanation. Using a plain yes could minimize the chances he wants to go into details.

I also see that this conversation depicted strongly derailed from the main query, which was yours asking if another approach could be considered to favor readability. Instead of answering to his question to if you know what is polymorphism I suggest you put the conversation back on track. The fact that polymorphism was cleverly applied is not much related to readability, which was what you asked.

When this happens, and this coworker responds with another question, put the conversation back on track: in this scenario it could have been by replying "Yes, it's clever use, but still I consider we can improve the readability by doing ...".

If you are not feeling chatty that moment, or you are in a hurry try not to engage on unrelated questions to your desired focus, so the topic does not derail into a 101 discussion about some specific detail.

Answer 2

I'm not sure if your example question is indicative of the questions you ask your coworker but one way to handle this would be to limit the scope of your questions to those with simple answers.

Answer 3

My team lead explains very thoroughly like this. Like you mentioned, it can be helpful when you don't fully understand a concept, but unnecessarily long when I do. I believe that if your colleague is willing to help you, it's likely he's not doing this in a malicious way. It's hard to tell what you do and do not know. When he ask "Do you know X?" and you feel like you understand X, just say "Yes I understand X." and move on.

I recommend being very direct with your questions and to drive the discussion as best you can. When I approach my team lead about a design question, I lay out the pro and cons of each options to where it's obvious I understand (or don't understand) key concepts. Then I have him give me his opinion about what's the best choice. At the end of the day, it's just a discussion and we're both human. You may rabbit hole a bit, go over things more than once and that's okay.