First, I have been in life insurance since 1982 and did it full time for 10 years, then kept my license up and "dabbled" since, but I do continuing ed each year for our state licensing, etc. (I do other things now, but keep in insurance license up).
I read some of the other responses and I tend to agree with their premise, but let me say that reading your statement carefully is that you "...just noticed I answered a question wrong....with the last 5 years...but...EVER...". So with this, I concluded that you did not try to "wiggle in", because it is an honest mistake. Especially if you are doing a term app by yourself and not having an agent "interview" you with the questions on the app, such a mistake is easy and common.
In this case, the liklihood (if you do not honestly correct the record now), is the the company may do what we call "underwrite on claim, not underwrite on issue". To clarify, companies underwrite (examine, investigate and issue your a policy or not) mostly on "issue" (when they issue the policy). At that, most companies have a two year incontestibility clause which states that after two years of the policy being in force, they will not contest suicide or any claim if there was no basis of evident fraud. Sometimes this used to be called the "suicide clause". You could take a policy out and at 2 years and one day, commit suicide and the company pays the claim.
So any death claim in the first two years the company is going to look for any reason not to pay the claim. After that, they consider themselves on the "hook" for most any claim. However, there are companies who notoriously "underwrite on claim". Yes, they "underwrite on issue", but they really do most of their underwriting investigation if there is a claim, to try to get out of paying the claim.
Reputable companies, after two years, will pay the claim without question, unless obvious fraud is brought to their attention. Nonetheless, discovering an error to your DUI question will be very detrimental to your heirs if your death is in a DUI related accident and the case files are opened to which the insurance claims investigator finds your history and compares it with the app.
What likely happens if they find you had an error on your app, and they are convinced it was a mistake, can nonethless contest the claim and in such a case as there is not outright fraud, the company will be liable contractuatlly to nothing more than "premiums paid". What this means is that say you pass on in 5 years; well after the 2 year incontestibility clause period. But you died in a car wreck with alcohol involved, the case gets reviewed and they find you said I "never had a DWI ever (though you thought it was just 5 years)", but find you did. They can deem this an invalid policy because it was put in force invalidly based on the new evidence of false original information, but since no fraud was committed (or pursued by the insurance company), they are obligated then to do no more than return premiums paid for the last 5 years. Say your premium was $500/yr x 5 is $2,500 and that is what the insurance company would pay your heirs. But your face value may have been $250,000, so the family/heirs lose out on $250,000, yet get the $2,500 of premiums paid back in this case.
Bottom line. Let the company know. If you have an agent, a good agent will take all relevant info from you and write a cover letter to the underwriter explaining your case and pleading for a "normal rating". The company may counter by saying: "OK, we'll offer coverage but at a "table 2"(for example only) (higher premium) for 3 years and if he continues to practice sobriety, we'll drop the rate to normal/standard from then on out. Better to pay a little more now and always have coverage later.
Good Luck