David Letterman's net worth is obviously that of an extremely rich man. With an annual salary of $20 million, who would dare say that this man is barely making both ends meet? However, reports say that compared to his previously $50 million-a-year salary, his wealth has obviously come down in recent years. Now, many are wondering if this is the main reason why Letterman is retiring.

The announcement of Letterman's departure from "The Late Show" indeed came as a surprise to his many fans.

According to National Post, David Letterman has now officially announced that he is retiring come 2015.

"The man who owns this network, Leslie Moonves, he and I have had a relationship for years and years and years, and we have had this conversation in the past, and we agreed that we would work together on this circumstance and the timing of this circumstance," David said in a statement. "And I phoned him just before the program and I said 'Leslie, it's been great, you've been great, and the network has been great, but I'm retiring.'"

Because of his shocking announcement, many fans began to wonder on why the famous TV personality has decided to step down from his hit show after 33 years.

CelebrityNetWorth wrote that in the past, David Letterman could easily earn as much as $50 million a year in licensing and syndication fees. However, today he only receives as much as $20 million, which is quite low compared to his salary history. Some speculated that this may have been the real reason why Letterman is retiring, and not just because he simply wants to take a rest from the showbiz industry.

Nonetheless, the speculation seems odd as David Letterman's net worth is actually $400 million, something that is already much too much to last his whole life through.

Fortunately, fans don't need to wonder anymore about David's decision. The famous TV personality, himself, already revealed the main reason why.

"I just want to reiterate my thanks for the support from the network, all of the people who have worked here, all of the people in the theater, all of the people on the staff, everybody at home, thank you very much," he said in a statement. "What this means now, is that Paul and I can be married."

Additionally, David also revealed that there isn't a precise timetable for his departure from the show, but he has made up his mind in stepping offstage by 2015.

"I think it will be at least a year or so, but sometime in the not too distant future, 2015 for the love of God, in fact, Paul and I will be wrapping things up," he said.

The announcement of David's retirement came just a few months after Jay Leno stepped down from hosting "The Tonight Show." While Leno was instantly replaced by Jimmy Fallon, it isn't clear yet who is going to replace Letterman.