If you had applied for a PR travel document at age 20, you probably would have gotten it but at 26, you can't really say that you are returning to Canada first chance after becoming an adult and it's not like you have any ties to Canada having spent only a month.
If you have been enrolled in full time studies from age 18 and until now, you can try it though and see what happens. That would be one option.
Another option would be to apply for your immigration from scratch under your own merits. Yet another would be to apply for a student visa, take a two year course, get a 3 year work permit afterwards and find a way to immigrate in the meantime.
However, if you apply for the PR travel document or your immigration and get denied, that can negatively effect applying for a student or other temporary visa as you have already stated that you would like to move to Canada permanently but as a student, you would be asking for a temporary visa and asking them to believe that you will not overstay.
One more option. You don't say where you are from. If you have a visa exempt passport to Canada and the USA or can get a visit visa to the USA, you could fly to the USA and enter Canada at the land border making the impression that you are just going on vacation. You could take with you no more luggage than for a regular vacation and you should not mention that you are a PR unless you are asked. If you are not reported for not meeting the residency obligation, you could theoretically stay for 2 years in order to put your PR status back in good standing. When you apply to renew your PR card two years later, you will meet the RO again. However, this method involves staying in Canada for 2 years straight without leaving and without applying for anything from immigration. With an expired PR card, you may well have problems getting a drivers license and health care. If you have a SIN since 10 years ago, you can check with Service Canada if it's dormant, ask to reactivate it and work. If you never had a SIN, you would not be able to work because you can not apply for a SIN with an old COPR and expired PR card.
If you tried this entry to Canada from the US and immigration were to figure out that you are a PR and want to revoke your PR, you could appeal and stay in Canada at least until your appeal hearing which might not happen until 1-2 years later.
