How I Met Your Mother: Top “45 Days” Theories, Is it Aunt Robin in the End? [PHOTOS]

"How I Met Your Mother" creators Carter Bays and Craig Thomas have pulled a neat trick with Season 8, Episode 20: "The Time Travelers." HIMYM fans were treated to a fresh serving of mother teasers, and one important element was revealed: Ted Mosby is only 45 days away from meeting the titular mother.

This week's HIMYM episode has sparked a lot of speculations from fans of the series. One theory is that Mosby becomes a widower, and he still somehow winds up with the kids' Aunt Robin. Another theory is that Ted has died, and his kids are only watching a video of him.

Here are some of the things we've seen in previous HIMYM episodes. Perhaps these things have helped formed the theory that Ted will eventually become a widower.

HIMYM: Ted reminds his kids that they used to draw their Aunt Robin memoirs. (Credit: CBS/How I Met Your Mother)

1. Robin Scherbatsky is not wearing a wedding ring in the HIMYM episode where Barney pulls the marinara sauce prank on Marshall. She is a clear flight risk on her wedding day, too. She is seen dancing with her father at the wedding reception, but other fans are betting she is not the bride at that wedding.

2. "Where's my wife?" In a college reunion episode, future versions of Ted, Lily, and Marshall got high. Ted later asks where his wife is, while laughing like crazy. It would be odd if he came with his wife and not have her close to him. This one of those "more on that later" previews that can lead to just about anything.

3. Aunt Robin drawings. Ted calls Marvin Eriksen his kids' cousin. No mention of Robin's kids has been made so far. But Ted reminds his kids that they used to draw their Aunt Robin in sweet children's memoirs. If it's a regular "family friends" thing, why is Marvin not around?

The creative team behind How I Met Your Mother producers has a huge task ahead. They will wrap up Season 8 with a major cliffhanger and start off Season 9 using a strikingly different approach. Fans can only build theories until then.

HIMYM: Ted reminds his kids that they used to draw their Aunt Robin memoirs. (Credit: CBS/How I Met Your Mother)