On Monday, Paul Ryan told the political world what we already knew: He's not running for president in 2016.

The operative question -- given that most data suggests the Wisconsin Congressman is both popular with the Republican electorate and performs well in 2016 ballot tests -- is why?

To answer that question you need to understand what Ryan is really saying: It's not that he doesn't have any interest in ever running for national office but rather that he doesn't have any interest in running for national office right now.

Remember that Ryan, at 44, is one of the youngest people mentioned as a potential presidential candidate for Republicans in 2016. (See the full age list here.)  Not only is he on the young end of that spectrum but he also has three young-ish children --none older than 13. Ryan, unlike most of the rest of the field, has the luxury of waiting four or even eight years without any danger of risking being cast as too old to run for the nation's top office. In eight years, say, Ryan's kids will be either in college or on their way to college and he will still only be in his early 50s.

Unlike many other people in the field, Ryan also has a safe political perch to pick his next moment in national politics. He's held his 1st district since 1998 without any real trouble -- that seat was once upon a time considered competitive -- and there's little reason to believe Democrats will mount a serious challenge to him. And, Ryan is about to enter his first of three terms -- six years -- as the chairman of the House Ways and Means Committee, a post he has long coveted. (Don't ask. Congress is weird.) So, not only does Ryan have a safe House seat but he has a job he's always wanted for the next half-decade (at least). And, not for nothing, it's a job with a pretty high profile -- particularly if Congress ever gets around to reforming the tax code.

Compare Ryan's situation to, say, that of Jeb Bush and Mitt Romney. Bush, who would be 64 on inauguration day 2017, has been out of elected office since 2006. Romney, who has lost not one but two presidential campaigns, would be nearly 70 on the day he was sworn in for a first term in 2017. For both men, running for president is a now-or-never proposition.  If they don't run now, it's difficult -- not impossible but difficult -- to see how they could have as good a chance in another race at some future date.

The Romney factor is also worth considering when answering the why-doesn't-Ryan-run question. By all accounts -- public and private -- Ryan and Romney formed a real friendship and bond during the 2012 campaign. Ryan, rather than stoke speculation about his own 2016 ambitions, has instead chose to urge Romney to re-consider his past denials of interest in running for a third time. "It is no secret that I have always thought Mitt would make a great president," Ryan told NBC on Monday. "As for his plans for 2016, I don't know what he is ultimately going to do and the last thing I want to do is get ahead of his own decision making process." (This Washington Post story notes that Romney called Ryan over the weekend to make clear he is serious about a third bid.)

Couple Romney's increasingly likely candidacy with the fact that Wisconsin Gov. Scott Walker, another Ryan friend and confidante, also appears to be moving toward the race and you have plenty of reason -- even if his age weren't a factor -- for Ryan to stay out. Which he is, smartly, doing.

Let the Ryan 2o24 speculation begin!