Vtyjkyuk

Sorry this got a little long...

I am self-studying a course. Two years ago I began to use some lectures by a professor from the United States (I'm from a different country). He is retired now. While watching his lectures, I began to have some questions about the topics. So I usually sent him an email which he usually replies to quickly. This has been going for a long time and I am extremely grateful that he almost always found time to answer my questions and even answer my follow up questions.

Last month, I sent him an email. He didn't respond. This is perfectly understandable because he might be very busy. The next day I sent him another email asking another question, and he responded to wait for a week before he can answer me because he has been very busy. I'm pretty ashamed at this point because I'm not sure if I am annoying him already.

Finally, yesterday I thought he is no longer busy, I sent him an email to ask another question. He responded something like this (not exact words):

Sorry it looks like I am ignoring you. I have been very busy and
answering your questions isn't a small amount of time.

Then proceeds to answer my question and asked if I understood.

Now I began to panic because he felt that he is ignoring me. The thing is I don't feel ignored at all. I know he's busy. In fact when I first started sending emails my hope is he would reply just a few times. I never expected he would help me a lot by always replying to my emails.

So my question is: how can I tell this professor that I don't feel ignore by him because I know he can be very busy and just answer my questions if he has the time? And also, if it matters, how can I express that I am extremely grateful he even answers my questions at all? I am not even one of his students. I just know about him through his lecture videos.

I am not sure what to do because I don't know the culture of the United States and I might offend him somehow by replying rashly. This professor has been very kind to me, and I do not wish to do something that might offend him.

A possible gushing response:

Him: "Sorry it looks like I am ignoring you. I have been very busy and answering your questions isn't a small amount of time."

You: "Professor (Name), I can't express how much I appreciate the time and effort that you put into answering my questions. You've been doing me a huge favor and helping in my studies more than I can say. I'm always happy to wait until you have time to answer, and if you're too busy to answer any longer, I will completely understand and still be immensely grateful for what you've done for me."

If he doesn't say, "Yes, I'm too busy, sorry," I would suggest that you probably wait for the response to each question before you send another question. If the delay is so long that you fear that he may not have even seen the last question, you might make an exception, but in general, I would suggest one question at a time.

You need to break your dependency on this professor, for your benefit and his.

It is entirely possible that he has been too busy recently and will resume "normal service" in due course. You just need to be patient and find some other way to get the answers you need. Maybe there is a Stack Exchange site on the subject you're studying, or some other internet resource, where you can ask a community your questions.

But another possibility is that you're becoming too much of a burden on him and he is being polite, withdrawing support on the basis of being "busy". He most likely doesn't want to leave you high and dry. But on the other hand he wants a life, and has indicated that your questions take a lot of his time. You have said this has been happening for a long time and maybe it has started to become too long, for him.

Edit as requested.

I think you're asking the wrong question. You would come across as extremely arrogant to let him know it's OK with you that he's busy for a while. He is not your servant and he doesn't owe you anything. On the contrary you owe him a great deal of thanks. Consequently my answer focuses on how I think you should respond to the current situation.

The direct answer then, in my opinion, is "You don't".

You mentioned the professor is retired now. To me his reply sounds like initially he thought you'd just be asking him one or two questions, but now you are basically using him like he's your professor with regular office hours. He's very politely letting you know not to bother him anymore and let him enjoy his retirement (he should be less busy now, shouldn't he?).

Don't tell him you don't mind, leave the guy alone.