(CNN) -- On January 14, 2013, George H.W. Bush was released from a Houston hospital after seven weeks of treatment for bronchitis, an infection and a persistent cough.
On Thursday he was sky-diving to celebrate his 90th birthday.
A year and a half ago, Bush was already suffering from a form of Parkinson's disease, and some people weren't sure how much he would be able to bounce back after his lengthy hospitalization. But not only has he been able to travel -- and now sky-dive -- he has also seen a political resurgence.
In April of last year, he attended the opening of his son's presidential library, telling the audience, "It's a great pleasure to be here to honor our oldest son."
In July, he visited the White House, where President Barack Obama recognized him for his commitment to volunteerism through his "Points of Light" initiative.
"We are surely a kinder and gentler nation because of you," Obama told Bush.
Just in the past month, he received several prestigious honors recognizing his decades of public service and his presidency. The proud Yale '48 graduate received an honorary degree from archrival Harvard, even attending the ceremony, and he also was given a Profile in Courage award by the JFK Library for the 1990 budget deal, which included the politically toxic tax hikes.
He admitted at the time that cutting the deal would probably cost him politically, and it did. He lost his re-election bid in 1992.
He and his presidency are now seen in a much better light than they were then.
Bush's earthbound celebration will be a dinner with 200 friends and family and a performance by Irish tenor Ronan Tynan.
His jump was a tandem one from a helicopter with Mike Elliott and members of the All Veteran Group, former members of the U. S. Army Golden Knights parachute team.
Bush also celebrated his 75th, 80th and 85th birthdays with jumps.
A just-released CNN/ORC International poll shows 58% of Americans now have a favorable opinion of Bush, compared with 47% in 1992. His poll numbers jumped to near 70% during the early days of his son George W. Bush's presidency.
His approval rating is second only to Bill Clinton's 66% rate among living presidents.
The 41st president marked the 25th anniversary of his inauguration this year. He and his wife, Barbara, attended a celebration event in April featuring hundreds of former administration officials, family and friends, who gathered at his presidential library in College Station, Texas. The Bushes attended some of the seminars examining his presidency and its effects and talked to many of the attendees.
"They just relished it," former Sen. Alan Simpson of Wyoming, a friend since the 1960s, said of the Bushes' reaction to the event.
Bush was especially touched, Simpson said, by the attendance of Democratic Sen. Tom Harkin of Iowa at the event that spotlighted their work together pushing the Americans with Disabilities Act, which Bush signed into law.
"History is sorting" through Bush's presidency now, and he is receiving more credit than while he was in office, Simpson said.
"Wait a minute -- the (Berlin) Wall came down ... this guy did things," he said.
"25 years ago this hour, the people placed their hopes and trust in our team. Still hard to believe I had the honor to serve as President," the former president posted on his Twitter account in January on the actual anniversary of his inauguration.
Ron Kaufman, a longtime friend and former Bush White House official, said, "History is going to be very, very kind to 41 for many reasons. ... Clearly there's a resurgence of people looking at 41, his lifetime and his presidency and after his presidency. ... Respect grows for him and for his family."
The former president, who had mostly stayed away from politics in recent years, now finds himself a big financial draw for Republicans thanks to his fascination with colorful socks. As of last week, the Republican National Committee said it had raised around $1 million selling pairs of striped yellow, orange, green and blue socks it created under Bush's name.
As for Bush's birthday and the attention it will bring, Simpson said, "I think he will say. 'I don't deserve this.' (But) the fact is, you (celebrate) the big 7-0, big 8-0, big 9-0 -- he'd be tickled to death."
Kaufman said Bush doesn't want people "puffing him up" and will leave it to history to judge his legacy.
"He really enjoys life to the fullest," he said.
Kaufman added that after Bush's illness, he is "less worried about death ... more enjoying his life as it is."
That includes shaving his head to show solidarity with the son of a member of his Secret Service detail who has cancer, and traveling to Duke University to honor Coach Mike Krzyzewski for his work supporting cancer research.
As for how the nation views him today, Simpson said Bush "is quite touched" by an outpouring of love and affection he receives from people across the nation.
"Wherever he goes, people love him," Kaufman said.