After being away from school for nine weeks in the latest lockdown, kids are returning to classes tomorrow as restrictions begin to ease.
Boris Johnson said he believes schools are "ready" for the restart and that children are itching to get back.
He added that tomorrow is "the big step on the roadmap that we hope is a roadmap to freedom".
The Prime Minister said: "It is made possible by the rollout of the vaccination programme. I'm very hopeful that it will work, it will all go according to plan and that all pupils will be back in schools."
The closures have hit millions hard.
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Kids missed out on classroom time and seeing friends, while teachers have been extremely busy trying to stop pupils falling too far behind.
And many parents have been tearing their hair out during homeschooling.
© REUTERSBoris Johnson says schools are ready
Talking at a vaccination centre in North London, Mr Johnson said: "I'm massively grateful to parents who have put up with so much... and teachers who have done an amazing job of keeping going.
"I do think we are ready. I think people want to go back."
The full reopening of schools and colleges is among the first shutdown relaxations in England.
From tomorrow, people will also be free to meet outside for recreation - such as coffee in a park - with one other person from a different household.
Education Secretary Gavin Williamson said the "whole nation" is looking forward to this week "with real excitement".
Public Health England's strategic adviser Dr Susan Hopkins said schools should also reopen after the Easter holidays even if the R rate rises above one, which would signify the virus is spreading again.
© PALabour leader Keir Starmer is urging ministers to launch catch-up breakfast clubs
She was upbeat about the continued lifting of lockdown curbs, saying: "I think we will hopefully all have our summer holidays."
But she told the BBC: "We will need to be ready for an autumn that could be challenging as these variants are there.
"We have to prepare for a hard winter. Not only with coronavirus but we've had a year of almost no respiratory viruses of any other type, and that means potentially the population immunity to that is less.
"So we could see surges in flu."
Experts think Covid cases will rise in the next few weeks, but by how many will be crucial to determining more relaxations.
Education chiefs are now looking at changes such as longer school days and shorter holidays.
Ofsted boss Amanda Spielman said similar ideas were not long-term successes previously.
She added pupils have been "lonely, bored, miserable" in lockdown and should get the full ration of school time, but that the Government must learn from the past.
She said if, for example, kids skip summer schools, a lot of effort may have been wasted.
Labour is urging ministers to launch catch-up breakfast clubs to help pupils recover time with friends and teachers.
Keir Starmer will kick off the party's Bright Future Taskforce with the aim of creating "a long-term strategy for children's recovery and ensuring every child has the chance to fulfil their potential".